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Opportunity Opportunity may refer to: Places * Opportunity, Montana, an unincorporated community, United States * Opportunity, Nebraska, an unincorporated community, United States * Opportunity, Washington, a former census-designated place, United States * ...
'' is a robotic
rover Rover may refer to: People Name * Constance Rover (1910–2005), English historian * Jolanda de Rover (born 1963), Dutch swimmer * Rover Thomas (c. 1920–1998), Indigenous Australian artist Stage name * Rover (musician), French singer-songw ...
that was active on the planet
Mars Mars is the fourth planet from the Sun. It is also known as the "Red Planet", because of its orange-red appearance. Mars is a desert-like rocky planet with a tenuous carbon dioxide () atmosphere. At the average surface level the atmosph ...
from 2004 to 2018. Launched on July 7, 2003, ''Opportunity'' landed on Mars'
Meridiani Planum Meridiani Planum (alternatively Terra Meridiani) is a large plain straddling the equator of Mars. The plain sits on top of an enormous body of sediments that contains bound water. The iron oxide in the spherules is crystalline (grey) hematite (Fe ...
on January 25, 2004, at 05:05
Ground UTC Spacecraft Event Time (SCET) is the spacecraft-local time for events that happen at the spacecraft. SCET is used for command programs that control the timing of spacecraft operations and to identify when specific events occur on the spacecraft rel ...
(about 13:15 Mars local time), three weeks after its twin '' Spirit'' (MER-A), also part of
NASA The National Aeronautics and Space Administration (NASA ) is an independent agencies of the United States government, independent agency of the federal government of the United States, US federal government responsible for the United States ...
's
Mars Exploration Rover Mission NASA's Mars Exploration Rover (MER) mission was a robotic space mission involving two Mars rovers, ''Spirit (rover), Spirit'' and ''Opportunity (rover), Opportunity'', exploring the planet Mars. It began in 2003 with the launch of the two rove ...
, touched down on the other side of the planet."Spirit" landed on January 4, 2004. While ''Spirit'' became immobile in 2009, and ceased communications in 2010, ''Opportunity'' exceeded its planned 90 sol (Martian days) duration of activity by 14 years 46 days (in Earth time). ''Opportunity'' continued to move, gather scientific observations, and report back to Earth until 2018. What follows is a summary of events during its continuing mission. ''Opportunity'' started in Eagle crater in 2004, literally landing inside on the crater basin, then it travelled outward making its way to Endurance crater. After this it went to Victoria crater, all the way making many panoramas, measurements, studying rocks, and smaller craters, even what are thought to be meteorites. It then traveled to Endeavour crater, where it has been making its way south along the Western rim. On June 10, 2018, contact was lost when a global dust storm blotted out the Sun, thus depriving the rover of enough power for operations, and communication with Earth. In September 2018, after the storm subsided, NASA began making various efforts to contact, and listen to the rover if it endured the storm. NASA officials declared that the ''Opportunity'' mission was complete on February 13, 2019, after it failed to wake from over 1,000 repeated signals sent since August 2018.


Mission timeline


Summary


Landing site context


2004


Landing site: "Eagle" crater

''Opportunity'' landed in
Meridiani Planum Meridiani Planum (alternatively Terra Meridiani) is a large plain straddling the equator of Mars. The plain sits on top of an enormous body of sediments that contains bound water. The iron oxide in the spherules is crystalline (grey) hematite (Fe ...
at , about downrange (east) of its intended target on January 25, 2004, at 05:05. Although Meridiani is a flat
plain In geography, a plain, commonly known as flatland, is a flat expanse of land that generally does not change much in elevation, and is primarily treeless. Plains occur as lowlands along valleys or at the base of mountains, as coastal plains, and ...
, without the rock fields seen at previous Mars landing sites, ''Opportunity'' rolled into an
impact crater An impact crater is a depression (geology), depression in the surface of a solid astronomical body formed by the hypervelocity impact event, impact of a smaller object. In contrast to volcanic craters, which result from explosion or internal c ...
22 meters in
diameter In geometry, a diameter of a circle is any straight line segment that passes through the centre of the circle and whose endpoints lie on the circle. It can also be defined as the longest Chord (geometry), chord of the circle. Both definitions a ...
, with the rim of the crater approximately from the rover. NASA Scientists were so excited about landing in a crater that they called the landing a "
hole in one In golf, a hole in one or hole-in-one (also known as an ace, mostly in American English) occurs when a ball hit from a tee to start a hole finishes in the cup. Holes-in-one most commonly occur on par 3 holes, the shortest distance holes on a sta ...
"; however, they were not aiming for the crater (and did not know it existed). Later, the crater was named '' Eagle crater'' and the landing site designated " ''Challenger'' Memorial Station". This was the darkest landing site ever visited by a spacecraft on Mars. It would be two weeks before ''Opportunity'' was able to get a better look at its surroundings. Scientists were intrigued by the abundance of rock outcrops dispersed throughout the crater, as well as the crater's soil, which appeared to be a
mixture In chemistry, a mixture is a material made up of two or more different chemical substances which can be separated by physical method. It is an impure substance made up of 2 or more elements or compounds mechanically mixed together in any proporti ...
of coarse gray grains, and fine reddish grains. This sweeping look at the unusual rock outcropping near ''Opportunity'' was captured by the rover's panoramic camera. Scientists believe the seemingly layered rocks are either volcanic ash deposits or sediments laid down by wind or water. It was given the name ''Opportunity Ledge''. Geologists said that the layers—some no thicker than a finger—indicate the rocks likely originated either from sediments carried by water or wind, or from falling volcanic ash. "We should be able to distinguish between those two hypotheses", said Dr. Andrew Knoll of Harvard University, Cambridge, a member of the science team for ''Opportunity,'' and its twin, ''Spirit''. If the rocks are sedimentary, water is a more likely source than wind, he said. These layered rocks measure only tall, and are thought to be either volcanic ash deposits or sediments carried by water or wind. The layers are very thin measuring just a few millimeters thick in some cases.


"Opportunity Ledge" outcroppings

On Sol 15, ''Opportunity'' took a close up of the rock "Stone Mountain" in the outcrop area of the crater, raising speculation that the rock consisted of very fine grain or dust, in contrast to Earth
sandstone Sandstone is a Clastic rock#Sedimentary clastic rocks, clastic sedimentary rock composed mainly of grain size, sand-sized (0.0625 to 2 mm) silicate mineral, silicate grains, Cementation (geology), cemented together by another mineral. Sand ...
, which is compacted sand with rather large grains. The
weathering Weathering is the deterioration of rocks, soils and minerals (as well as wood and artificial materials) through contact with water, atmospheric gases, sunlight, and biological organisms. It occurs '' in situ'' (on-site, with little or no move ...
agent eroding away layers of this rock seemed to be visible as dark spots. A picture received on February 10 (taken on Sol 16) showed that the thin layers in the bedrock converge, and diverge at low angles, suggesting that some "moving current" such as volcanic flow, wind, or water formed these rocks. The discovery of these layers was significant for scientists who had planned this mission to test the "water hypothesis" rigorously.


El Capitan outcropping

On February 19 the survey of "Opportunity Ledge" was declared successful. A specific target in the outcrop (dubbed "El Capitan"), whose upper and lower portions appeared to differ in layering and weathering characteristics, was selected for further investigation. El Capitan, about high, was named after a mountain in Texas. ''Opportunity'' reached El Capitan on Sol 27, and took a first picture of the rocks with its panoramic camera. On Sol 30, ''Opportunity'' used its
Rock Abrasion Tool The Rock Abrasion Tool (RAT) is a grinding and brushing installation on NASA’s twin Mars Exploration Rovers, '' Spirit'' (MER-A) and '' Opportunity'' (MER-B), which landed on Mars in January 2004. It was designed, developed and continues to be o ...
(RAT) for the first time to investigate the rocks around El Capitan. The image on the right-hand side shows a close-up view taken after the drilling and cleaning process was complete. Due to chance, two spherules were also cut partially, and seem to show scratches, and other marks made by the diamond-crusted grind tool. The black areas are artifacts of the imaging process, when parts of the picture are missing. During a press conference on Sol , March 2, 2004, mission scientists discussed their conclusions about the bedrock and the evidence for the presence of liquid water during their formation. They presented the following reasoning to explain the small, elongated voids in the rock visible on the surface, and after grinding into it (see last two images below). These voids are consistent with features known to geologists as "
vug A vug, vugh, or vugg () is a small- to medium-sized cavity inside rock. It may be formed through a variety of processes. Most commonly, cracks and fissures opened by tectonic activity ( folding and faulting) are partially filled by quartz, calc ...
s". These are formed when crystals form inside a rock matrix and are later removed through erosive processes, leaving behind voids. Some of the features in this picture are "disk-like", which is consistent with certain types of crystals, notably sulfate minerals. Additionally, mission members presented first data from the
MIMOS II MIMOS II is the miniaturised Mössbauer spectrometer, developed by Dr. Göstar Klingelhöfer at the Johannes Gutenberg University in Mainz, Germany, that is used on the Mars Exploration Rovers '' Spirit'' and ''Opportunity'' for close-up investig ...
Mössbauer spectrometer taken at the bedrock site. The iron spectrum obtained from the rock El Capitan shows strong evidence for the mineral
jarosite Jarosite is a basic hydrous sulfate of potassium and ferric iron (Fe-III) with a chemical formula of KFe3(SO4)2(OH)6. This sulfate mineral is formed in ore deposits by the oxidation of iron sulfides. Jarosite is often produced as a byproduct dur ...
. This mineral contains
hydroxide Hydroxide is a diatomic anion with chemical formula OH−. It consists of an oxygen and hydrogen atom held together by a single covalent bond, and carries a negative electric charge. It is an important but usually minor constituent of water. It ...
ions, which indicates the presence of water when the minerals were formed. Mini-TES data from the same rock showed that it consists of a considerable amount of sulfates. Image:Opportunity photo of Mars outcrop rock.jpg, Close up of a rock outcrop. Image:Opp layered sol17-B017R1 br.jpg, Thin rock layers, not all parallel to each other. Image:Xpe First Opp RAT-B032R1 br.jpg, Section of hole created by RAT. Image:17-jg-03-mi2-B035R1_br.jpg, Voids or "vugs" inside the rock.


Analyzing soil through digging a trench

In order to analyze the soil inside the crater it was decided to try to dig a trench with the wheels. The rover alternately pushed soil forward and backward out of the trench with its right front wheel while other wheels held the rover in place. The rover turned slightly between bouts of digging to widen the hole. The process lasted 22 minutes. The resulting trench — the first dug by either Mars Exploration Rover — is about long and deep. Two features that caught scientists' attention were the clotty texture of soil in the upper wall of the trench, and the brightness of soil on the trench floor. By inspecting the sides and floor of a hole it dug, ''Opportunity'' found some things it had not imaged beforehand, including shiny round pebbles and soil so fine-grained that the rover's microscope could not make out individual particles. What is underneath is different from what is at the immediate surface. The soils consist of fine-grained basaltic sand and a surface lag of hematite-rich spherules, spherule fragments, and other granules. Underlying the thin soil layer, are flat-lying sedimentary rocks. These rocks are finely laminated, are rich in sulfur, and contain abundant sulfate salts.S. Squyres, ''et al.'', "The Opportunity Rover's Athena Science Investigation At Meridiani Planum, Mars," ''Science, Vol. 306'', Issue 5702, 1698–1703 (December 3, 2004).


Endurance crater

On sol April 20, 2004, the rover reached Endurance crater, which was known to have many layers of rocks. In May the rover circumnavigated the crater, and made observations with Mini-TES and the panoramic camera. The rock "Lion Stone" was investigated on Sol 107 and found to be similar in composition to the layers found in Eagle crater. On sol June 4, 2004 mission members announced their intention to drive ''Opportunity'' into Endurance, even if it should turn out to be impossible to get back out, targeting the various rock layers that were identified in the pictures from the crater rim. "This is a crucial and careful decision for the Mars Exploration Rovers' extended mission", said Dr. Edward Weiler, NASA's associate administrator for space science. Steve Squyres, principal investigator from Cornell University said: "Answering the question of what came before the evaporites is the most significant scientific issue we can address with ''Opportunity'' at this time." A first drive into the crater was executed on sol June 8, and ''Opportunity'' backed out again the same day. It was found that the angle of the surface was well inside the safety margin (about 18 degrees), and the full excursion toward the rock layer of interest was started. During Sols 134 (June 12), 135, and 137 the rover drove deeper and deeper into the crater. Although some wheel slip was observed, driving was discovered to be possible even at slope angles up to 30 degrees. Wispy
clouds In meteorology, a cloud is an aerosol consisting of a visible mass of miniature liquid droplets, frozen crystals, or other particles, suspended in the atmosphere of a planetary body or similar space. Water or various other chemicals may c ...
, similar to Earth's
cirrus cloud Cirrus ( cloud classification symbol: Ci) is a genus of high cloud made of ice crystals. Cirrus clouds typically appear delicate and wispy with white strands. In the Earth's atmosphere, cirrus are usually formed when warm, dry air rises, causing ...
s, were spotted. ''Opportunity'' spent roughly 180 sols inside the crater, before backing out of it again in mid December 2004, on Sol 315. Scientific results of the sedimentary geology of the crater were published in the journal ''
Earth and Planetary Science Letters ''Earth and Planetary Science Letters'' (EPSL) is a bimonthly peer-reviewed scientific journal covering research on physical, chemical and mechanical processes of the Earth and other planets, including extrasolar ones. Topics covered range from de ...
'' In December 2004, daily power output varied from 840 watt-hours while inside Endurance Crater to 730 watt-hours on the plains.


2005


Heat Shield Rock and stuck in sand

After exiting Endurance crater, in January 2005 ''Opportunity'' was driven to examine its own discarded
heat shield In engineering, a heat shield is a component designed to protect an object or a human operator from being burnt or overheated by dissipating, reflecting, and/or absorbing heat. The term is most often used in reference to exhaust heat management a ...
. While in the vicinity of the heat shield, on Sol 345 it came upon an object that was immediately suspected and soon confirmed to be a
meteorite A meteorite is a rock (geology), rock that originated in outer space and has fallen to the surface of a planet or Natural satellite, moon. When the original object enters the atmosphere, various factors such as friction, pressure, and chemical ...
. The meteorite was promptly named
Heat Shield Rock Heat Shield Rock is a basketball-sized iron-nickel meteorite found on the Meridiani Planum plain of Mars by the Mars rover ''Opportunity'' in January 2005. Informally referred to as "Heat Shield Rock" by the Opportunity research team, the met ...
, and is the first meteorite identified on another planet (although the Bench Crater and
Hadley Rille Hadley may refer to: Places Earth Canada * Hadley Bay, on the north of Victoria Island, Nunavut England * Hadley, London, a former civil parish within Barnet Urban District from 1894 to 1965 * Hadley, Shropshire, part of the new town of T ...
meteorites were found earlier on the
Moon The Moon is Earth's only natural satellite. It Orbit of the Moon, orbits around Earth at Lunar distance, an average distance of (; about 30 times Earth diameter, Earth's diameter). The Moon rotation, rotates, with a rotation period (lunar ...
). After about 25 sols of observations ''Opportunity'' headed south for a crater named Argo, nearly from the heat shield. The rover was commanded to dig another trench on the vast plains of Meridiani Planum, on Sol 366, and observations continued until Sol 373 (February 10, 2005). The rover then passed the craters "Alvin" and "Jason", and by Sol 387, approached a "crater triplet" on its way to Vostok Crater. Along the way, ''Opportunity'' set a distance record for one-day travel by either rover: , on sol February 19, 2005. On Sol (February 26, 2005), the rover approached one of the three craters, dubbed Naturaliste. A rock target named "Normandy" was chosen for investigation on Sol 392, and ''Opportunity'' remained there until Sol 395. ''Opportunity'' reached Vostok Crater on Sol 399, finding it mostly filled with sand and lined by outcrops. It was then ordered south into what has been called "etched terrain", to search for more bedrock. On March 20, 2005 (Sol 410) ''Opportunity'' set a new Martian record for the longest single day drive when it drove . By Sol 415, ''Opportunity'' stopped by some soil ripples to investigate the differences between soil in the trough of a ripple and its crest. Various soil targets included "Mobarak" in the trough, named in honor of Persian New Year, and "Norooz" and "Mayberooz" on the crest. By Sol 421, the rover left the ripple for "Viking" crater. Between April 26, 2005 (Sol 446) and June 4, 2005 (Sol 484) ''Opportunity'' was stuck in a Martian sand dune. The problem began on sol (April 26, 2005) when ''Opportunity'' inadvertently dug itself into a sand dune: Mission scientists reported that images indicated all four corner wheels were dug in by more than a wheel radius, just as the rover attempted to climb over a dune about tall. The sand dune was designated "Purgatory Dune" by mission planners. The rover's condition was simulated on Earth prior to any attempt to move, out of concern that the rover might become permanently immobilized. After various simulations intended to mimic the properties and behavior of Martian sand were completed, the rover executed its first wheel movements on sol (May 13, 2005), intentionally advancing only a few centimeters, after which mission members evaluated the results. During Sol 465 and 466 more drive commands were executed, and with each trial the rover moved another couple of centimeters. At the end of each movement, panoramic images were acquired to investigate the atmosphere and the surrounding dune field. The sand dune escape maneuver was successfully completed on sol (June 4, 2005), and all six wheels of ''Opportunity'' were on firmer ground. After studying "Purgatory" from Sol 498 to Sol 510, ''Opportunity'' proceeded southward toward "Erebus crater".


Erebus crater

''Opportunity '' studied Erebus crater, a large, shallow, partially buried crater and a stopover on the way south toward Victoria crater, between October 2005 and March 2006. New programming to measure the percentage of slip in the wheels was successful in preventing the rover from getting stuck again. Another "Purgatory"-like incident was averted on Sol 603, when onboard slip check software stopped a drive after slip reached 44.5%. It proceeded over many ripples and 'half-pipes', taking photographs after each sol's journey. On Sol (November 3, 2005) ''Opportunity'' woke up in the midst of a mild dust storm that lasted three days. The rover was able to drive in self-protective auto-mode during the storm, but it could not take any post-drive images. Less than three weeks later, another
cleaning event __NOTOC__ A cleaning event is a phenomenon whereby dust is removed from solar panels, in the context of exploration and science rovers on Mars, supposedly by the action of wind. The term is used on several NASA webpages; generally supposing th ...
cleared the dust off of the solar array so as to produce around 720 watt-hours (80% of max). On Sol (December 1, 2005), it was discovered the motor used to stow the robotic arm for travel was stalling. This problem took nearly two weeks to fix. Initially, the arm was stowed only for travel and was extended at night to prevent the arm from getting stuck. However, further stalling convinced engineers to leave the arm extended at all times to avoid the arm becoming stuck in the stowed position and becoming unusable. ''Opportunity'' observed numerous outcroppings around Erebus crater. It also collaborated with ESA's
Mars Express ''Mars Express'' is a space exploration mission by the European Space Agency, European Space Agency (ESA) exploring the planet Mars and its moons since 2003, and the first planetary mission attempted by ESA. ''Mars Express'' consisted of two ...
by using the miniature
Thermal Emission Spectrometer The Thermal Emission Spectrometer (TES) was an instrument on board Mars Global Surveyor. TES collected two types of data, hyperspectral thermal infrared data from 6 to 50 micrometres (μm) and bolometric visible-near infrared (0.3 to 2.9 μm) me ...
and panoramic camera (Pancam), and took images of a transit across the Sun by Phobos. On Sol (March 22, 2006), ''Opportunity'' began the journey to its next destination, Victoria crater, which it would reach in September 2006 (Sol 951). It would stay at Victoria crater until August 2008 (Sol 1630–1634).


Shoulder troubles

The "shoulder" joint of ''Opportunity''s arm has had troubles since Sol 2 (January 25, 2004), the rover's second day on Mars. Engineers discovered that the heater on the shoulder azimuth joint, which controls side-to-side motion of the robotic arm, was stuck in the "on" position. Closer investigation revealed that the on-off switch had probably failed during assembly, test, and launch operations on Earth. Fortunately for ''Opportunity'', the rover was equipped with a built-in safety mechanism called a "T-stat box" (thermostatic switch) that provided protection against overheating. When the shoulder azimuth joint, also known as Joint 1, got too hot, the T-stat switch automatically opened and temporarily disabled the heater. When the joint got cold again, the T-stat closed. As a result, the heater stayed on all night but not all day. The safety mechanism worked until ''Opportunity'' approached the first winter on Mars. As the Sun began to retreat lower in the sky and solar power levels dropped, it became clear that ''Opportunity'' would not be able to keep the batteries charged with a heater draining power all night long. On Sol (May 28, 2004), rover operators began using a procedure known as "deep sleep," during which ''Opportunity'' disconnected the batteries at night. Deep sleep prevented the stuck heater (and everything else on the rover except the clock and the battery heaters) from drawing power. When the Sun came up the next morning and sunlight began hitting the solar arrays, the batteries automatically reconnected, the robotic arm became operational, the shoulder joint warmed up, and the thermostatic switch opened, disabling the heater. As a result, the shoulder joint was extremely hot during the day and extremely cold at night. Such huge temperature swings, which tend to make electric motors wear out faster, were taking place every sol. This strategy worked for ''Opportunity'' until Sol 654 (November 25, 2005), when the Joint-1 azimuth motor stalled because of increased electrical resistance. Rover operators responded by delivering higher-than-normal current to the motor. This approach also worked, though Joint 1 continued to stall periodically. Typically, the rover's handlers simply tried again the next sol and the joint worked. They determined that the Joint-1 motor stalls were most likely due to damage caused by the extreme temperature cycles the joint experienced during deep sleep. As a precaution, they started keeping the robotic arm out in front of the rover overnight, rather than stowing it underneath the rover deck, where it would be virtually unusable in the event of a Joint-1 motor failure. They stowed the arm only while driving and unstowed it immediately at the end of each drive.


2006


Journey to Victoria crater

On March 22, 2006 (Sol 760), ''Opportunity'' left Erebus crater and began the journey to Victoria crater, which it reached in September 2006 (Sol 951). It would stay at Victoria crater until August 2008 (Sol 1630–1634).


Arrival at Victoria crater

Victoria crater Victoria is an impact crater on Mars located at 2.05°S, 5.50°W in the Meridiani Planum extraterrestrial plain, lying situated within the Margaritifer Sinus quadrangle (MC-19) region of the planet Mars. This crater was first visited by the Mars E ...
is a massive impact crater approximately from the original landing site. Victoria's diameter is six times larger than Endurance crater. Scientists believed that rock outcrops along the walls of Victoria would yield more information about the geologic history of Mars, if the rover survived long enough to investigate them. On Sol (September 26, 2006) Opportunity reached the rim of Victoria Crater and transmitted the first substantial views of Victoria, including the dune field at the bottom of the crater. The
Mars Reconnaissance Orbiter The ''Mars Reconnaissance Orbiter'' (''MRO'') is a spacecraft designed to search for the existence of water on Mars and provide support for missions to Mars, as part of NASA's Mars Exploration Program. It was launched from Cape Canaveral on Au ...
photographed Opportunity at the rim of the crater.


2007


Moving around Victoria's rim

On January 4, 2007, both rovers received new flight software for their computers. The update was received just in time for the third anniversary of their landing. The new systems let the rovers decide whether to transmit an image, and whether to extend their arms to examine rocks, which would save much time for scientists, as they would not have to sift through hundreds of images to find the one they want, or examine the surroundings to decide to extend the arms and examine the rocks. The APXS instrument was now for the first time used to determine the amount of the
noble gas The noble gases (historically the inert gases, sometimes referred to as aerogens) are the members of Group (periodic table), group 18 of the periodic table: helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), radon (Rn) and, in some ...
argon Argon is a chemical element; it has symbol Ar and atomic number 18. It is in group 18 of the periodic table and is a noble gas. Argon is the third most abundant gas in Earth's atmosphere, at 0.934% (9340 ppmv). It is more than twice as abu ...
in the atmosphere of Mars. The same measurements were done on the other side of the planet by its rover twin Spirit. The purpose of this experiment was to determine the atmospheric mixing processes and track their changes with time. In January the rover drove along the north side of the crater rim and imaged the cliffs from different viewpoints. While driving another meteorite was found: ''Santa Caterina''. In March the ''Valley without peril'' was reached. This point had thought to be a possible entry point into the crater. But it turned out that this point had a too steep slope to drive carefully downside. After two additional cliffs where inspected it was decided to drive the whole way back to the point, where ''Opportunity'' arrived at Victoria crater. On June 15, 2007, the rover arrived at Duck Bay and prepared for entering the crater. A series of
cleaning event __NOTOC__ A cleaning event is a phenomenon whereby dust is removed from solar panels, in the context of exploration and science rovers on Mars, supposedly by the action of wind. The term is used on several NASA webpages; generally supposing th ...
s beginning on Sol (April 20, 2007) allowed ''Opportunity''s
solar energy Solar energy is the radiant energy from the Sun's sunlight, light and heat, which can be harnessed using a range of technologies such as solar electricity, solar thermal energy (including solar water heating) and solar architecture. It is a ...
production to rise to above 800 watt-hours per Sol. By Sol (May 4, 2007) the solar array current was peaking above 4.0
ampere The ampere ( , ; symbol: A), often shortened to amp,SI supports only the use of symbols and deprecates the use of abbreviations for units. is the unit of electric current in the International System of Units (SI). One ampere is equal to 1 c ...
s, values not seen since Sol (February 10, 2004). However, the advent of extensive dust storms on Mars starting in mid-2007 (in-line with Mars' six Earth-year global dust storm cycle), dropped energy production levels to 280 watt-hours per day.


Dust storms

Toward the end of June 2007, a series of dust storms began clouding the Martian atmosphere with dust. The storms intensified and by July 20, both ''Opportunity'' and ''Spirit'' were facing the real possibility of system failure due to lack of power. NASA released a statement to the press that said (in part) "We're rooting for our rovers to survive these storms, but they were never designed for conditions this intense". The key problem caused by the dust storm was a dramatic reduction in solar power. There was so much dust in the atmosphere that it blocked 99 percent of direct sunlight to the rover. The ''Spirit'' rover, on the other side of the planet, was getting slightly more sunlight than ''Opportunity''. Normally the solar arrays are able to generate about 700 watt-hours of energy per day. During the storms, the power generated is greatly reduced. If the rovers get less than 150 watt-hours per day they have to start draining their batteries. If the batteries run dry, key electrical elements are likely to fail due to the intense cold. On July 18, 2007, the rover's solar-panel only generated 128 watt-hours, the lowest level ever. NASA responded by commanding Opportunity to only communicate with Earth once every three days, the first time that this had happened since the start of the mission. The dust storms continued through July and at the end of the month, NASA announced that the rovers, even under their very-low-power mode were barely getting enough energy to survive. If the temperature of the ''Opportunity''s electronics module continued to drop, according to the announcement, "there is a real risk that Opportunity will trip a low-power fault. When a low-power fault is tripped, the rover's systems take the batteries off-line, putting the rover to sleep and then checking each sol to see if there is sufficient available energy to wake up and perform daily fault communications. If there is not sufficient energy, Opportunity will stay asleep. Depending on the weather conditions, Opportunity could stay asleep for days, weeks or even months, all the while trying to charge its batteries with whatever available sunlight there might be." It was quite possible that the rover would never wake up from a low-power fault. By sol August 7, 2007 the storms appeared to be weakening, and although power levels were still low they were sufficient for ''Opportunity'' to begin taking and returning images. By August 21 dust levels were still improving, the batteries were fully charged and ''Opportunity'' was able to make its first drive since the dust storms began. ''Opportunity'' made a short drive into Duck Bay on sol September 11, 2007 and then reversed out again to test traction on the initial slope into Victoria Crater. On sol September 13, 2007 it returned to begin a more thorough exploration of the inner slope, examining a series of layers of pale-coloured rock in the upper parts of Duck Bay and the face of the promontory
Cape Verde Cape Verde or Cabo Verde, officially the Republic of Cabo Verde, is an island country and archipelagic state of West Africa in the central Atlantic Ocean, consisting of ten volcanic islands with a combined land area of about . These islands ...
in detail. File:Victoria crater from HiRise.jpg, Victoria crater (HiRise). Image:Opportunity at Victoria Crater from Mars reconnaissance orbiter.jpg, ''Opportunity'' at the rim of Victoria Crater, as imaged by MRO (October 3, 2006). Image:Oppland01.jpg, ''Opportunity'' at the rim of Victoria Crater, as imaged by MRO (November 29, 2006). Image:Opportunity Tracks.jpg, ''Opportunity'' tracks, as seen by HiRISE. The white dots are places where rover stopped to perform scientific observations or turned (6/2007).


2008

Rover daily power output averaged 580 watt-hours in the first days of 2008, with atmospheric opacity (tau) caused by dust at about 0.71, and solar array dust factor averaging 0.787.


Inspecting Victoria crater

On Sol 1502 (April 15, 2008) the motor stalled at the beginning of an unstowing operation at the end of a drive, when the arm was still tucked underneath the rover. The motor continued to stall on all subsequent attempts, sol after sol. Engineers performed tests at various times of day to measure electrical resistance. They found that the resistance was lowest (essentially normal) when the joint was at its warmest—in the morning, following deep sleep, after the heater had been on for several hours, and just before the T-stat opened. They decided to try to unstow the arm one more time under these conditions. At 08:30 local Mars time on Sol (May 14, 2008), they allowed ''Opportunity'' to direct as much current as possible to the warm, joint-1 azimuth motor in order to get the robotic arm into a usable position, in front of the rover. It worked. Because ''Opportunity'' will likely never again stow the robotic arm, engineers devised a strategy for driving the rover safely with the arm deployed in front.


Departing Victoria crater

The rover exited Victoria crater's Duck Bay on August 24–28, 2008 (sol 1630–1634). Before exiting the crater the rover experienced a current spike similar to the one that preceded the malfunction of the right front wheel of its twin ''Spirit''. After Victoria crater and during its journey to Endeavour crater the rover investigated sets of "dark cobbles" on the Meridiani plains. Endeavour is in diameter and is south-east of Victoria. Rover drivers estimated that this distance could be traversed in about two years. Scientists expected to see a much deeper stack of rock layers at the crater than those examined by ''Opportunity'' in Victoria. The discovery of phyllosilicate clay-bearing rock on the Endeavour crater rim promised exposure to a rock-type that is even more hospitable to life than types previously analyzed. The solar conjunction, where the Sun is between Earth and Mars, started on sol November 29, 2008 and communication with the rovers was not possible until December 13, 2008. During this time the rover team planned to have ''Opportunity'' use the Mössbauer spectrometer to examine a rock outcrop named "Santorini".


2009


Driving through Meridiani plains

On sol (March 7, 2009) ''Opportunity'' first saw the rim of Endeavour after driving about since it left Victoria in August 2008. ''Opportunity'' also saw Iazu crater that was about away and is about in diameter. On sol (April 7, 2009) ''Opportunity'' generated 515 watt-hours after a cleaning event of the solar arrays increased energy production by about 40%. From April 16 to 22 (sol 1859 to 1865) ''Opportunity'' made a series of drives and during that week traveled a total distance of . The drive actuator for the right front wheel, which had been rested while ''Opportunity'' studied a rock outcrop called "Penrhyn", had motor currents very close to normal levels.


More meteorite findings

On sol (July 18, 2009) a large dark rock was noted in the opposite direction from which ''Opportunity'' was traveling and so the rover headed toward it, reaching it on sol (July 28). The rock turned out to be a meteorite and was named Block Island. ''Opportunity'' spent until September 12, 2009 (Sol 2004) investigating the meteorite, before returning to its journey toward Endeavour Crater. Its journey was interrupted on Sol 2022 by the find of another meteorite, a specimen dubbed 'Shelter Island', which the rover investigated until Sol 2034. It then headed for another meteorite, 'Mackinac Island', which it reached four sols later on sol (October 17, 2009). The rover conducted a drive-by imaging sequence but otherwise did not investigate this meteorite, resuming its journey to Endeavour. On sol (November 10, 2009) the rover reached a rock target of interest, named 'Marquette Island'. Prolonged study until sol January 12, 2010 ensued, as it was uncertain what type of rock this represented, but the eventual conclusion was that it was rock ejecta from deep within the surface of Mars rather than a meteorite. Image:Endeavour Crater Annotated 2009-03-07.jpg, Annotated image showing the position of Opportunity on March 7, 2009, and names for the craters Iazu, Endeavour, and Victoria. Image:Opportunity Eyes Block Island.jpg, On July 18, 2009 ''Opportunity'' imaged an oddly shaped, dark rock, which was found to be a meteorite. Image:Block Island Meteorite on Mars.jpg, ''Opportunity'' prepares to inspect the unusual rock, now dubbed Block Island. It is the largest meteorite found by a Martian rover so far. Image:Opportunity Rover Approaches Marquette Island.jpg, ''Opportunity'' took this picture of a rock informally named 'Marquette Island' as it approached the rock for investigations that have suggested the rock is a stony meteorite.


2010


Concepción

On January 28, 2010 (Sol 2138) ''Opportunity'' arrived at Concepcion crater. ''Opportunity'' successfully circumnavigated the diameter crater before continuing on towards Endeavour. Energy production varied from about 305 watt-hours to about 270 Wh during this period. On sol (May 5, 2010), due to potentially hazardous dune fields along the direct path between Victoria and Endeavour, a new route was charted that extended the distance to travel between the two craters to . On (May 19, 2010), ''Opportunity'' reached sols of operation, making it the longest Mars surface mission in history, breaking the record of 2245 sols set by ''
Viking 1 ''Viking 1'' was the first of two spacecraft, along with '' Viking 2'', each consisting of an orbiter and a lander, sent to Mars as part of NASA's Viking program. The lander touched down on Mars on July 20, 1976, the first successful Mars lan ...
''.


Santa Maria crater

In July 2010, it was announced that the ''Opportunity'' team would use the theme of names given to places visited by British
Royal Navy The Royal Navy (RN) is the naval warfare force of the United Kingdom. It is a component of His Majesty's Naval Service, and its officers hold their commissions from the King of the United Kingdom, King. Although warships were used by Kingdom ...
Captain Captain is a title, an appellative for the commanding officer of a military unit; the supreme leader or highest rank officer of a navy ship, merchant ship, aeroplane, spacecraft, or other vessel; or the commander of a port, fire or police depa ...
, Lieutenant
James Cook Captain (Royal Navy), Captain James Cook (7 November 1728 – 14 February 1779) was a British Royal Navy officer, explorer, and cartographer famous for his three voyages of exploration to the Pacific and Southern Oceans, conducted between 176 ...
, in his 1769–1771 Pacific Ocean voyage in command of HMS ''Endeavour'', for informal names of sites at
Endeavour Crater Endeavour is an impact crater located in the Meridiani Planum extraterrestrial plain within the Margaritifer Sinus quadrangle (MC-19) region of the planet Mars. Endeavour is about in diameter. Using ''Mars Reconnaissance Orbiter'' data, phy ...
. These would include "
Cape Tribulation Cape Tribulation is a headland and coastal locality in the Shire of Douglas in northern Queensland, Australia. In the , Cape Tribulation had a population of 123 people. Geography The locality is north of Cairns. It is within the Daintree N ...
" and " Cape Dromedary", " Cape Byron" (the most easterly point of the Australian mainland), and "
Point Hicks Point Hicks (formerly called Cape Everard), is a coastal headland in the East Gippsland region of Victoria, Australia, located within the Croajingolong National Park. The point is marked by the Point Hicks Lighthouse that faces the Tasman Se ...
" (the part of the Australian mainland first sighted by the ''Endeavour'' in 1770). On sol (September 8, 2010), the halfway point of the journey between Victoria crater and Endeavour crater was reached. In November the rover spent a few days imaging a crater called Intrepid while navigating through a field of small impact craters. On sol November 14, 2010 total odometry passed the mark. Average solar array energy production in October and November was about 600 watt-hours. On sol (December 15, 2010) the rover arrived at Santa Maria and spent several weeks investigating the wide crater. The results from ''Opportunity'' were compared to data taken from orbit by the CRISM instrument, a spectrometer, on the ''
Mars Reconnaissance Orbiter The ''Mars Reconnaissance Orbiter'' (''MRO'') is a spacecraft designed to search for the existence of water on Mars and provide support for missions to Mars, as part of NASA's Mars Exploration Program. It was launched from Cape Canaveral on Au ...
''. CRISM had detected water-bearing minerals at Santa Maria crater, and the rover helped further analyze this. ''Opportunity'' drove farther in that Martian year (that is about 2 Earth years), than in any previous year.


2011


Heading to Endeavour crater

After its arrival at the edge of Santa Maria crater, the team positioned the rover at its southeastern rim and collected data. They also prepared for the two-week solar conjunction of late January, when the Sun was between Earth and Mars and communication was blocked. In late March ''Opportunity'' began the journey between Santa Maria and Endeavour, and on June 1, the rover passed the traverse milestone (over 50 times its designed distance). Two weeks later, on sol (July 17, 2011), ''Opportunity'' had driven on Mars. By sol (August 29, 2011), ''Opportunity'' had continued to function effectively 30 times longer than its planned 90- sol mission, aided by solar cell
cleaning event __NOTOC__ A cleaning event is a phenomenon whereby dust is removed from solar panels, in the context of exploration and science rovers on Mars, supposedly by the action of wind. The term is used on several NASA webpages; generally supposing th ...
s, and performed extensive geological analysis of Martian rocks and planetary surface features with its instruments.


Endeavour crater arrival

''Opportunity'' arrived at
Endeavour crater Endeavour is an impact crater located in the Meridiani Planum extraterrestrial plain within the Margaritifer Sinus quadrangle (MC-19) region of the planet Mars. Endeavour is about in diameter. Using ''Mars Reconnaissance Orbiter'' data, phy ...
on sol (August 9, 2011), at a landmark called ''Spirit Point'' named after its rover twin, after traversing from
Victoria crater Victoria is an impact crater on Mars located at 2.05°S, 5.50°W in the Meridiani Planum extraterrestrial plain, lying situated within the Margaritifer Sinus quadrangle (MC-19) region of the planet Mars. This crater was first visited by the Mars E ...
, over a three-year period. Endeavour is wide and offers scientists new terrain to explore, including older rocks than encountered heretofore, and clay minerals that may have formed in the presence of water. The rover's deputy principal investigator, Ray Arvidson, said it will probably not enter Endeavour crater as it appears to contain material observed previously. The rocks on the rim are older than any previously studied by ''Opportunity''. "I think there's much more interest in driving around the perimeter of the rim," said Arvidson. The rover survived so long this goal was accomplished, and by 2016 it was decided to not only enter Endevaour crater but also explore, for the first time in history what is thought to be a water carved gully on Mars (update:2016). Upon arriving at Endeavour, ''Opportunity'' almost immediately began discovering Martian phenomena not previously observed. On sol (August 22, 2011) the rover began examining Tisdale 2, a large ejecta block. "This is different from any rock ever seen on Mars," said
Steve Squyres Steven Weldon Squyres (born January 9, 1956) is an American geologist and planetary scientist. He was the James A. Weeks Professor of Physical Sciences at Cornell University in Ithaca, New York. His research area is in planetary sciences, with a ...
, principal investigator for ''Opportunity'' at Cornell University in Ithaca, New York. "It has a composition similar to some volcanic rocks, but there's much more zinc and bromine than we've typically seen. We are getting confirmation that reaching Endeavour really has given us the equivalent of a second landing site for Opportunity." (See also
Cape York (Mars) Cape York is a location on Mars, on the western rim of Endeavour crater. The Opportunity rover, ''Opportunity'' rover spent about two years exploring this portion of the rim in the early 2010s before moving south. The CRISM instrument on the ''M ...
) In December the ''Homestake'' formation was analyzed, which was concluded to be formed of
gypsum Gypsum is a soft sulfate mineral composed of calcium sulfate Hydrate, dihydrate, with the chemical formula . It is widely mined and is used as a fertilizer and as the main constituent in many forms of plaster, drywall and blackboard or sidewalk ...
. Using three of the rover's instruments - the Microscopic Imager, the Alpha Particle X-Ray Spectrometer and the Panoramic Camera's filters - researchers determined the deposit to be hydrated calcium sulfate, or gypsum, a mineral that does not occur except in the presence of water. This discovery was called "slam dunk" evidence that "water flowed through underground fractures in the rock." ''Opportunity'' had driven more than by November 22, 2011 (sol 2783), as preparations were made for the coming Martian winter. It moved to terrain that positioned it about 15 degrees to the north, an angle more favorable for
solar energy Solar energy is the radiant energy from the Sun's sunlight, light and heat, which can be harnessed using a range of technologies such as solar electricity, solar thermal energy (including solar water heating) and solar architecture. It is a ...
production during the
Martian Mars, the fourth planet from the Sun, has appeared as a setting in works of fiction since at least the mid-1600s. Trends in the planet's portrayal have largely been influenced by advances in planetary science. It became the most popular celes ...
winter.


2012


Greeley Haven

In January 2012 the rover returned data from Greeley Haven, named after the geologist Ronald Greeley, while enduring its fifth Martian winter. It studied the Martian wind, which has been described as "the most active process on Mars today", and conducted a radio science experiment. By carefully measuring radio signals, wobbles in Martian rotation may show whether the planet has a solid or liquid interior. The winter worksite sits on the Cape York segment of the rim of Endeavour Crater. ''Opportunity'' reached the edge of this crater in August after three years of driving from smaller Victoria Crater, which it studied for two years. On Sol 2852 (February 1, 2012) the energy production from the solar array was 270 watt-hours, with a Mars atmospheric opacity (Tau) of 0.679, a solar array dust factor of 0.469, with total
odometry Odometry is the use of data from motion sensors to estimate change in position over time. It is used in robotics by some legged or wheeled robots to estimate their position relative to a starting location. This method is sensitive to errors due ...
at . By March (around Sol 2890), 'Amboy' rock was studied with the
MIMOS II MIMOS II is the miniaturised Mössbauer spectrometer, developed by Dr. Göstar Klingelhöfer at the Johannes Gutenberg University in Mainz, Germany, that is used on the Mars Exploration Rovers '' Spirit'' and ''Opportunity'' for close-up investig ...
Mössbauer spectrometer and the Microscopic Imager, and the amount of
Argon Argon is a chemical element; it has symbol Ar and atomic number 18. It is in group 18 of the periodic table and is a noble gas. Argon is the third most abundant gas in Earth's atmosphere, at 0.934% (9340 ppmv). It is more than twice as abu ...
gas in the Martian air was measured. The Mars
winter solstice The winter solstice, or hibernal solstice, occurs when either of Earth's geographical pole, poles reaches its maximum axial tilt, tilt away from the Sun. This happens twice yearly, once in each hemisphere (Northern Hemisphere, Northern and So ...
passed on March 30, 2012 (Sol 2909) and on April 1 there was a small cleaning event. On Sol 2913 (April 3, 2012) solar array energy production was 321 watt-hours. The mission of Mars rover ''Opportunity'' continued, and by May 1, 2012 (Sol 2940), energy production had increased to 365 watt-hours, with the solar array dust factor at 0.534. The team prepared the rover for movement and finished up collecting data on Amboy rock. 60 Doppler radio passes were completed over the winter. On May 8, 2012 (Sol 2947), the rover moved . On that day the Solar energy production was 357 watt-hours with a solar array dust factor of 0.536. ''Opportunity'' had been stationary on Greeley Haven for 130 Sols (Mars' days), with a 15 degrees tilt to the North to help survive the winter; after the drive the northerly tilt decreased to 8 degrees. The drive marked the end of the
geodynamics Geodynamics is a subfield of geophysics dealing with dynamics of the Earth. It applies physics, chemistry and mathematics to the understanding of how mantle convection leads to plate tectonics and geologic phenomena such as seafloor spreading, ...
science experiment, which used radio Doppler measurements while the rover was stationary. By June 2012, it studied Mars dust and a nearby rock vein christened "Monte Cristo" as it headed North.


Exploring Matijevic hill at Cape York

On July 2, 2012 ''Opportunity''s 3000 Sols on Mars were celebrated. By July 5, 2012, NASA published a new panorama (seen below) showing the surroundings of ''Opportunity'' at the Greeley Haven position at Cape York. Also, the other end of the Endeavour crater is seen in the right half of the scene, a crater that spans in diameter. On July 12, 2012 (Sol 3010), solar arrays produced 523 watt-hours and was the total distance traveled from landing. That month,
Mars Reconnaissance Orbiter The ''Mars Reconnaissance Orbiter'' (''MRO'') is a spacecraft designed to search for the existence of water on Mars and provide support for missions to Mars, as part of NASA's Mars Exploration Program. It was launched from Cape Canaveral on Au ...
spotted a dust storm and water ice clouds near the rover. Before ''
Curiosity Curiosity (from Latin , from "careful, diligent, curious", akin to "care") is a quality related to inquisitive thinking, such as exploration, investigation, and learning, evident in humans and other animals. Curiosity helps Developmental psyc ...
'' landed on August 6, 2012, ''Opportunity'' sent special Ultra High Frequency radio signals to simulate ''Curiosity'' for a radio observatory in Australia. August activities for ''Opportunity'' included collecting data on atmospheric opacity, visiting ''Sao Rafael'' and ''Berrio'' craters, and achieving of driving on Sol 3056 (August 28, 2012). Also, on August 19, 2012
Mars Express ''Mars Express'' is a space exploration mission by the European Space Agency, European Space Agency (ESA) exploring the planet Mars and its moons since 2003, and the first planetary mission attempted by ESA. ''Mars Express'' consisted of two ...
orbiter automatically exchanged data with both ''Curiosity'' and ''Opportunity'' in one orbit, its first double contact. In the fall ''Opportunity'' headed south, exploring Matijevic hill and searching for phyllosilicate minerals. Some data was sent to Earth directly using X-Band radio signals, as opposed to orbiter relays. Finally, the number of power cycles on the rover's Inertial Measurement Unit were reduced. Science work included testing various hypotheses about the newly discovered spherules.


2013


Leaving Cape York

Opportunity began the year at the edge of Endeavour Crater's Cape York, and the total distance travelled since landing on Mars was . After completing work at Matijevic Hill the ''Opportunity'' rover headed south to the rim of Endeavour Crater. Next, the rover headed south across a gap in the rim to a place the researchers called Botany Bay, then up onto the next rim segment to the south. There are two hills to the south of it, one called Solander Point and farther south is Cape Tribulation. The current aim is for ''Opportunity'' to reach Solander Point before winter reaches the Martian southern hemisphere as the area has ground tilted to the north allowing the rover to stay active during the winter months. In addition Solander Point has a large geological stack for Opportunity to explore. In April 2013, the rover passed through a three-week-long solar conjunction, when communication with Earth was blocked because of the Sun. The rover arm was positioned on a rock during that time so the APXS could collect data. On May 16, 2013, NASA announced that ''Opportunity'' had driven further than any other NASA vehicle on a world other than Earth. After ''Opportunity''s total odometry went over it surpassed the total distance driven by the
Apollo 17 Apollo 17 (December 7–19, 1972) was the eleventh and final mission of NASA's Apollo program, the sixth and most recent time humans have set foot on the Moon. Commander Gene Cernan and Lunar Module Pilot Harrison Schmitt walked on the Moon, ...
Lunar Roving Vehicle The Lunar Roving Vehicle (LRV) is a Battery electric vehicle, battery-powered four-wheeled Rover (space exploration), rover used on the Moon in the last three missions of the American Apollo program (Apollo 15, 15, Apollo 16, 16, and Apollo 17 ...
. The record for longest distance driven by a vehicle on another world was as of 2013 held by the
Lunokhod 2 ''Lunokhod 2'' ( ("Moonwalker 2"), also known as Аппарат 8ЕЛ № 204 ("Device 8EL No. 204")) was the second of two uncrewed space mission, uncrewed lunar rover (space exploration), rovers that landed on the Moon by the Soviet Union as ...
lunar rover A lunar rover or Moon rover is a space exploration Rover (space exploration), vehicle designed to move across the surface of the Moon. The Apollo program's Lunar Roving Vehicle was driven on the Moon by members of three American crews, Apollo 15, ...
. Based on wheel rotations Lunokhod 2 was thought to have covered , but Russian scientists have revised that to an estimated distance of about based on orbital images of the lunar surface. On May 17, 2013, NASA announced that a preliminary analysis of one of the rock targets, named " Esperance", suggested that water in the past may have had a neutral pH. This was later confirmed in further studies, supporting the notion that ancient Mars was a "water-rich world with conditions amenable for life". As of June 20, 2013 (Sol 3344), ''Opportunity''s total odometry was reported at , while en route to 'Solander Point.' June 21, 2013 marked five
Martian year Though no standard exists, numerous calendars and other timekeeping approaches have been proposed for the planet Mars. The most commonly seen in the scientific literature denotes the time of year as the Ecliptic coordinate system, number of degre ...
s on the 'red planet'. The project manager, noting the harsh conditions of the planet, has said each day is "a gift".


Solander Point

By early July 2013 ''Opportunity'' was approaching Solander Point, with daily drives ranging from dozens of meters (yards) to over a hundred. It arrived at its base in early August 2013, after investigating a curious terrain patch along the way. Solander could provide a northward facing slope to aid in sunlight collection, as the Martian winter was approaching (as the season changes, the angle of the Sun is shifting). On Sol 3390 (August 6, 2013) energy intake was 385 watt-hours, down from 395 on Sol 3384 (July 31, 2013), and 431 on Sol 3376 (July 23, 2013). In May 2013 it had been as high as 546 watt-hours. Other factors that impact collection include the atmospheric opacity (i.e. "Tau") and "solar array dust factor"dust that collects on the panels. Although the rover cannot clean the dust off, such systems were considered for the rover during its development. In September, numerous surface targets and rocks around Solander were examined by the rover. Solar array energy production dropped to 346 watt-hours by Sol 3430 (September 16, 2013), and 325 watt-hours by Sol 3452 (October 9, 2013). By traveling to locations with favorable tilt, dubbed "lily pads", ''Opportunity'' managed to receive over about 300 watt-hours per day even as the heart of the Mars winter approached. The Martian winter minimum was predicted for February 2014, but by making use of the northward slopes the rover had enough power to remain mobile during the Martian winter. By the end of October the rover was climbing up Solander point, where it was hoped some of the oldest rocks yet seen would be examined. The rocks were believed to date to Mars's
Noachian The Noachian is a system (stratigraphy), geologic system and early geologic timescale, time period on the planet Mars characterized by high rates of meteorite and asteroid Impact event, impacts and the possible presence of abundant surface water. ...
Period about four billion years ago, and could have provided some science surprises by Christmas. The team was hunting for "juicy" slopes of 5 to 20 degrees for more power. As it ascended, it doglegged in early November to avoid an area of dusty ripples. It continued to collect data on Martian rocks and dust in the area. Total odometry by November 5, 2013 (or in Mars days since the landing, Sol 3478) was . Energy production from the Sun on that date was 311 watt-hours, with Tau at 0.536 and the dust factor at 0.491. Before ''Spirit'' rover stopped responding in 2010, it reported 134 watt-hours as temperatures plunged below minus 41.5 degrees Celsius (minus 42.7 degrees Fahrenheit). By early December power levels had hit 270 watt-hours per day, even as it climbed higher up the ridge. It maintained a northerly tilt to increase energy production on Solander point. In early December one of the communication relay satellites at Mars, Odyssey, had some difficulties so the rover sent its telemetry directly to Earth. The orbiter returned to operation after December 10, 2013, and the rover prepared for additional drives. On Sol 3521 (Dec. 19, 2013) the rover took micro-images and used the Alpha Particle X-ray Spectrometer. Between December 31 and New Year's Day cleaning events removed dust, improving the Solar Array Dust Factor to 0.566 (where higher is better and 1.0 is totally clean). Energy production increased 35 watt-hours/day after this cleaning, to 371 watt-hours/day.


2014

''Opportunity'' started off 2014 on the western ridge of Endeavour crater, providing elevated panoramas of the surrounding region. Research on data from Mars orbiters identified interesting minerals on the outcrop. Some communication and difficulties the previous month delayed investigating these rocks, but on the positive side, the wait, along with a cleaning event over January 1, allowed for more electrical power to be available. The rover is tilted towards the Sun to help it get more power, and it is expected that it can remain active during the Martian winter.


Pinnacle Island

On January 17, NASA reported that a
rock Rock most often refers to: * Rock (geology), a naturally occurring solid aggregate of minerals or mineraloids * Rock music, a genre of popular music Rock or Rocks may also refer to: Places United Kingdom * Rock, Caerphilly, a location in Wale ...
, named " Pinnacle Island", that was not in a rover image taken on Sol 3528, "mysteriously" appeared 13 days later in a similar image taken on Sol 3540. One possible explanation, presented by Steven Squyres, principal investigator of the
Mars Exploration Rover Mission NASA's Mars Exploration Rover (MER) mission was a robotic space mission involving two Mars rovers, ''Spirit (rover), Spirit'' and ''Opportunity (rover), Opportunity'', exploring the planet Mars. It began in 2003 with the launch of the two rove ...
, was that the rover, in one of its turning motions, flicked the rock from a few meters away and into the new location. In response,
Rhawn Joseph The ''Journal of Cosmology'' is a website that describes itself as a "scientific journal". It has been criticized for lacking oversight and proper peer-review, and promoting fringe theories. It was established in 2009 by neuroscientist Rhawn Jose ...
published an article in the fringe journal '' Journal of Cosmology'' on January 17, 2014, and filed a writ of
mandamus A writ of (; ) is a judicial remedy in the English and American common law system consisting of a court order that commands a government official or entity to perform an act it is legally required to perform as part of its official duties, o ...
on January 27, 2014, in San Francisco Federal Court, stating that the object is a living entity and demanded that NASA re-examine the rock more closely. However, NASA already had examined the rock with the rover's
microscope A microscope () is a laboratory equipment, laboratory instrument used to examine objects that are too small to be seen by the naked eye. Microscopy is the science of investigating small objects and structures using a microscope. Microscopic ...
and analyzers, and confirmed it was a rock with a high sulphur, manganese, and magnesium content. According to Steven Squyres, "We have looked at it with our microscope. It is clearly a rock." On February 14, 2014, NASA released an image showing the location from where the " Pinnacle Island" rock was dislodged by the ''Opportunity'' rover.


Renewed focus

On January 23, 2014, NASA celebrated the tenth anniversary (officially, January 25, 2014) of the rover's landing on Mars by sharing a self-portrait of the rover from above. They also reported on the latest discoveries of some Martian rocks and stated, "These rocks are older than any we examined earlier in the mission, and they reveal more favorable conditions for
microbial life A microorganism, or microbe, is an organism of microscopic scale, microscopic size, which may exist in its unicellular organism, single-celled form or as a Colony (biology)#Microbial colonies, colony of cells. The possible existence of unseen ...
than any evidence previously examined by investigations with ''Opportunity''." On January 24, 2014, NASA reported that current studies on the planet
Mars Mars is the fourth planet from the Sun. It is also known as the "Red Planet", because of its orange-red appearance. Mars is a desert-like rocky planet with a tenuous carbon dioxide () atmosphere. At the average surface level the atmosph ...
by the ''Curiosity'' and ''Opportunity'' rovers will now be searching for evidence of ancient life, including a
biosphere The biosphere (), also called the ecosphere (), is the worldwide sum of all ecosystems. It can also be termed the zone of life on the Earth. The biosphere (which is technically a spherical shell) is virtually a closed system with regard to mat ...
based on
autotroph An autotroph is an organism that can convert Abiotic component, abiotic sources of energy into energy stored in organic compounds, which can be used by Heterotroph, other organisms. Autotrophs produce complex organic compounds (such as carbohy ...
ic,
chemotroph A chemotroph is an organism that obtains energy by the oxidation of electron donors in their environments. These molecules can be organic ( chemoorganotrophs) or inorganic ( chemolithotrophs). The chemotroph designation is in contrast to phot ...
ic and/or chemolithoautotrophic
microorganism A microorganism, or microbe, is an organism of microscopic scale, microscopic size, which may exist in its unicellular organism, single-celled form or as a Colony (biology)#Microbial colonies, colony of cells. The possible existence of unseen ...
s, as well as ancient water, including fluvio-lacustrine environments (
plain In geography, a plain, commonly known as flatland, is a flat expanse of land that generally does not change much in elevation, and is primarily treeless. Plains occur as lowlands along valleys or at the base of mountains, as coastal plains, and ...
s related to ancient
river A river is a natural stream of fresh water that flows on land or inside Subterranean river, caves towards another body of water at a lower elevation, such as an ocean, lake, or another river. A river may run dry before reaching the end of ...
s or
lake A lake is often a naturally occurring, relatively large and fixed body of water on or near the Earth's surface. It is localized in a basin or interconnected basins surrounded by dry land. Lakes lie completely on land and are separate from ...
s) that may have been
habitable Habitability is the adequacy of an environment for human living. Where housing is concerned, there are generally local ordinances which define habitability. If a residence complies with those laws, it is said to be habitable. In extreme environ ...
. The search for evidence of
habitability Habitability is the adequacy of an environment for human living. Where housing is concerned, there are generally local ordinances which define habitability. If a residence complies with those laws, it is said to be habitable. In extreme environ ...
,
taphonomy Taphonomy is the study of how organisms decay and become fossilized or preserved in the paleontological record. The term ''taphonomy'' (from Greek language, Greek , 'burial' and , 'law') was introduced to paleontology in 1940 by Soviet scientis ...
(related to
fossils A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...
), and
organic carbon Total organic carbon (TOC) is an analytical parameter representing the concentration of organic carbon in a sample. TOC determinations are made in a variety of application areas. For example, TOC may be used as a non-specific indicator of wa ...
on the planet
Mars Mars is the fourth planet from the Sun. It is also known as the "Red Planet", because of its orange-red appearance. Mars is a desert-like rocky planet with a tenuous carbon dioxide () atmosphere. At the average surface level the atmosph ...
is now a primary
NASA The National Aeronautics and Space Administration (NASA ) is an independent agencies of the United States government, independent agency of the federal government of the United States, US federal government responsible for the United States ...
objective. Among many activities in March 2014, the rover studied the rock "Augustine," and on Sol 3602 (March 12, 2014), produced 498 watt-hours from sunlight. Two cleaning events in March 2014 significantly boosted available power. Since January 2013, the solar array dust factor (one of the determinants of solar power production) varied from a relatively dusty 0.467 on December 5, 2013 (sol 3507) to a relatively clean 0.964 on May 13, 2014 (sol 3662). On July 28, 2014, NASA announced that ''Opportunity'', after having traveled over on the planet
Mars Mars is the fourth planet from the Sun. It is also known as the "Red Planet", because of its orange-red appearance. Mars is a desert-like rocky planet with a tenuous carbon dioxide () atmosphere. At the average surface level the atmosph ...
, has set a new "off-world" record as the
rover Rover may refer to: People Name * Constance Rover (1910–2005), English historian * Jolanda de Rover (born 1963), Dutch swimmer * Rover Thomas (c. 1920–1998), Indigenous Australian artist Stage name * Rover (musician), French singer-songw ...
having driven the greatest distance, surpassing the previous record held by the Soviet Union's Lunokhod 2 rover that had traveled . After a series of "resets" pointed to problems with flash memory, the rover stopped driving from late August to early September, 2014, in order to reformat its flash memory. Though minor memory problems persisted in the immediate aftermath of reformatting, they did not hinder the rover's continued operation; ''Opportunity'' resumed driving towards "Ulysses" crater and "Marathon Valley," exceeding total odometry of 41 kilometers by November 11, 2014.


2015

2015 was a year of superlative achievements for the MER-B mission, starting off with summiting
Cape Tribulation Cape Tribulation is a headland and coastal locality in the Shire of Douglas in northern Queensland, Australia. In the , Cape Tribulation had a population of 123 people. Geography The locality is north of Cairns. It is within the Daintree N ...
in January 2015, which was the highest elevation achieved yet on its mission. Then in March 2016 it accomplished the distance of a classic
marathon The marathon is a long-distance foot race with a distance of kilometres ( 26 mi 385 yd), usually run as a road race, but the distance can be covered on trail routes. The marathon can be completed by running or with a run/walk strategy. There ...
. Also in March 2016 it achieved the steepest slope traverse (32 degree) yet of its mission, surpassing the slope it took on at Burns Cliff in 2004. MER-B was trying to reach a target on Knudsen Ridge, on the south side of Marathon Valley, which meant attempting a steep grade which can cause wheel slippage. Another effect of this angle was that sand and dust that had collected on the rover flowed in streaks over the back of the rover, such was the incline. In 2015 MER-B entered Marathon Valley and would study it until September 2016. On March 23, 2015, NASA reported ''Opportunity'' flash memory was successfully reformatted. After completing analysis of the flash memory issues, engineers concluded that some of the problems stemmed from a single memory bank, one of ''Opportunity'' seven "banks" of onboard flash memory. A software upgrade was sent which allows the rover to bypass this bank, known as Bank 7. By February 2015, total odometry exceeded 42 kilometers. From July to September, the rover mostly operated using a RAM-only mode, to avoid ongoing flash memory issues. In September, a series of tests were performed to better understand the volatility of the device. During the beginning of October 2015, ''Opportunity'' began its drive to north-tilted slopes in Marathon Valley of the west rim of Endeavour crater in preparation for the Martian winter. By November 2, after attempting to use the rover's flash memory, ''Opportunity'' again suffered an "amnesia" event. and the decision was made to switch back to use RAM on November 11 (Sol 4195).


2016

On January 3, 2016 (Sol 4246), ''Opportunity'' went through the winter solstice on Mars with already improved
solar insolation Solar irradiance is the power per unit area ( surface power density) received from the Sun in the form of electromagnetic radiation in the wavelength range of the measuring instrument. Solar irradiance is measured in watts per square metre ...
, with the rover producing 449 watt-hours from its solar panels. On January 25, 2016, ''Opportunity'' had marked twelve years since landing on Mars and continued its scientific investigation of Marathon Valley. On March 31, 2016, ''Opportunity'' captured an image of a dust devil inside Endeavour crater. Although the ''Spirit'' rover saw dust devils frequently, they have been less common in the area that ''Opportunity'' is exploring.


Marathon Valley Panorama

In June 2016, MER-B took a special panoramic image called the ''Sacagawea Panorama'' in honor of Sacagawea, the Lemhi Shoshone woman that helped the
Lewis and Clark Expedition The Lewis and Clark Expedition, also known as the Corps of Discovery Expedition, was the United States expedition to cross the newly acquired western portion of the country after the Louisiana Purchase. The Corps of Discovery was a select gro ...
on their journey of exploration across America in 1804 to 1806. The image was taken of Marathon Valley at Endeavour Crater on the planet Mars. On the right side of this image is "Knudsen Ridge", and beyond Marathon valley is the floor of Endeavor crater. In the distance is the rim of crater on the other side.


Marathon Valley departure

In September 2016, ''Opportunity'' departed from Marathon Valley which it traversed through over the previous Earth year. As it continued to explore the Western rim of Endeavor crater, it was directed out of Lewis and Clark gap in Marathon valley, and made its way towards Spirit mound. By early October 2016, the rover had reached Spirit mound by passing through Bitterroot valley, where it began to collect data on a science target. Starting in October 2016, the three new mission goals include driving down into Endeavour Crater along what is thought to be a water-carved gully, compare the material on the plains to the interior of the crater, and to find pre-impact rocks (rocks that pre-date the impact that presumably formed Endeavour crater). By October 4, 2016, the rover had traveled , and generated 472 watt-hours of electricity. This date was mission time of Sol (Mars days) 4514. The gully in the above annotated picture is a few hundred meters from the rover, and is the location of the suspected fluid-carved, possibly water, gullies that have never been investigated from the surface before. One of the MER-B goals is to drive down to this gully and examine it.


Imaging ''Schiaparelli''s descent

In October 2016 the ESA ''Schiaparelli'' lander attempted to land near Endeavour crater, and the two teams worked together for ''Opportunity'' to possibly image the lander during its descent. ''Opportunity'' did take pictures of the area of the sky the lander was coming down in although the lander was not identified at that time; the nature of MER-B's cameras, the terrain, and the uncertainty of the lander's location, meant imaging was not a certainty. By late October 2016 it was confirmed Schiaparelli had crashed into the surface rather than achieving a soft touchdown.


Moving on

The rover headed south from Spirit point after the events of ExoMars, continuing its mission on the edge of Endeavour crater. On Sol 4541 (Nov. 1, 2016), the solar array energy production is 390 watt-hours and on Sol 4548 (Nov. 8, 2016), the solar array energy production is 445 watt-hours. A readout from the EEPROM was returned to Earth, this is used in the test-bed rovers on Earth.


2017

On Sol 4623 (January 24, 2017 PST) the team celebrated 13 years operating ''Opportunity'' on the surface of Mars. By February 7, 2017 (Sol 4636) the rover had traveled on the surface of Mars. Power collection from the Sun on that date was 414 watt-hours. The long-term goal at the time was a gully south of the rover on the Western rim of Endeavour crater. Science operations also continued including microscopic imaging of select rocks, APXS operation, and atmospheric
argon Argon is a chemical element; it has symbol Ar and atomic number 18. It is in group 18 of the periodic table and is a noble gas. Argon is the third most abundant gas in Earth's atmosphere, at 0.934% (9340 ppmv). It is more than twice as abu ...
gas measurements. Throughout 2017, ''Opportunity'' worked its way south along the Western rim as it moved towards the gully, which the team named ''Perseverance Valley'' in April 2017. Some other names considered for this feature were Perseverance Gulch, Perseverance Ravine, and Perseverance Gorge. It is a valley network that runs downslope in the Cape Bryon section of Western rim of Endeavour crater. The Martian winter reached its hardest time for the rover this year, with reduced sunlight and colder temperatures. One strategy the Rover team uses is to position the Rover on northward faced slopes to get more sunlight, and because the gully runs east–west, they were often able to use the southern edge of the gully channel of Perseverance Valley to tilt the rover this way. The Martian winter solstice was in November 2017, and it is the 8th one that MER-B has passed through. Some energy production readings from 2017:


Up to 4836 (September 2017)

Rover arrives at the Gully (Perseverance Valley) and heads into it, taking measurements and pictures, but also had to survive the Mars winter (November Winter Solstice).


2018

In 2018 the rover continued to explore the area called Perseverance Valley, which is on the western rim of Endeavor Crater. The feature was previously called "Gully" and it was named by the rover team in early 2017. The rover reached Perseverance Valley (the gully) in 2017 and spent the rest of the year exploring this area. In 2018 this in-depth study continued. The Valley may have a previously unknown type of rock. It is thought to be a fluid-carved channel, a spillway from the surrounding planes down to the crater floor. Among the candidates for what carved the channels are water, but also ice or wind currents. One of the ongoing questions is the idea of ancient water on Mars, and how it may have impacted the modern Mars environment. In the 2010s NASA has been on the hunt for ancient fossils left by tiny living organisms especially when they make large colonies, such as
Stromatolite Stromatolites ( ) or stromatoliths () are layered Sedimentary rock, sedimentary formation of rocks, formations (microbialite) that are created mainly by Photosynthesis, photosynthetic microorganisms such as cyanobacteria, sulfate-reducing micr ...
s, which look like mushroom shaped rocks but are made by colonies of bacteria. The question of ancient bacteria on Mars was raised in the 1990s, when a scientist thought he had found microscopic bacterial fossils on a meteorite that came from Mars (see ALH84001) but was found on Earth. Future missions, such as
Mars 2020 Mars 2020 is a NASA mission that includes the rover ''Perseverance (rover), Perseverance'', the now-retired small robotic helicopter ''Ingenuity (helicopter), Ingenuity'', and associated delivery systems, as part of the Mars Exploration Progra ...
, will carry more advanced chemical and geological detectors to Mars with them; some images taken by ''Opportunity'' have led to speculation about whether the images contain evidence of
extraterrestrial life Extraterrestrial life, or alien life (colloquially, aliens), is life that originates from another world rather than on Earth. No extraterrestrial life has yet been scientifically conclusively detected. Such life might range from simple forms ...
. One example, as reported by ''
National Geographic ''National Geographic'' (formerly ''The National Geographic Magazine'', sometimes branded as ''Nat Geo'') is an American monthly magazine published by National Geographic Partners. The magazine was founded in 1888 as a scholarly journal, nine ...
'', appears to show a
cauliflower Cauliflower is one of several vegetables cultivated from the species '' Brassica oleracea'' in the genus '' Brassica'', which is in the Brassicaceae (or mustard) family. Cauliflower usually grows with one main stem that carries a large, rou ...
-shaped rock in an image taken by the ''Spirit'' rover in 2007, which, to some scientists, resembled fossils of microscopic
stromatolites Stromatolites ( ) or stromatoliths () are layered sedimentary formations ( microbialite) that are created mainly by photosynthetic microorganisms such as cyanobacteria, sulfate-reducing bacteria, and Pseudomonadota (formerly proteobacteria) ...
, which are ubiquitous on Earth, and represent the earliest widely accepted example of life in Earth's biosphere. Stromatolites, thought to be signs of some of the earliest life discovered on Earth, almost 4 billion years ago, are on Earth today. Another candidate are
cynobacteria Cyanobacteria ( ) are a group of autotrophic gram-negative bacteria that can obtain biological energy via oxygenic photosynthesis. The name "cyanobacteria" () refers to their bluish green (cyan) color, which forms the basis of cyanobacteria' ...
which are also determined to be among the oldest life on Earth. Because of the large impacts that eject matter into space Mars has exchanged material with over long time scales, leading some to suggest life could make the journey between Earth and Mars. Indeed, cynobacteria survived for almost two-years in space (Aboard ISS) and could still come alive again when put in life conditions after being in zero-g, zero-air, high radiation conditions common to outer space. On the colonization side, cyanobacteria like
nostoc ''Nostoc'', also known as star jelly, troll's butter, spit of moon, fallen star, witch's butter (not to be confused with the fungi commonly known as witches' butter), and witch's jelly, is the most common genus of cyanobacteria found in a variety ...
colonies that have been studied for terraforming are known to survive on Mars regolith simulant and lower pressures. Some the evidence for ancient water include the discovery of minerals that form in the presence of water, such as
Jarosite Jarosite is a basic hydrous sulfate of potassium and ferric iron (Fe-III) with a chemical formula of KFe3(SO4)2(OH)6. This sulfate mineral is formed in ore deposits by the oxidation of iron sulfides. Jarosite is often produced as a byproduct dur ...
, discovered by ''Opportunity'' at Eagle Crater in 2004. (see also
Martian spherules Martian spherules (also known as hematite spherules, blueberries, & Martian blueberries) are small spherules (roughly spherical pebbles) that are rich in an iron oxide (grey hematite, α-Fe2O3) and are found at Meridiani Planum (a large plain on M ...
) ''Opportunity'' studied the rock target Jornada del Muerto in Perseverance Valley, using its surviving suite of instruments including the Microscopic Imager (MI), APXS, and the color cameras. At this time rocks from the Matijevic Formation have not been found, and the valley is proving to have some complicated natures One area being studied is how the dust flows through channel and makes deposits. On Sol 4977 (Jan. 23, 2018), the stored backup flight software was updated to the latest version. On that day electrical production was 644 watt-hours, and total distance traveled on Mars since landing was . On Sol 4999 (Feb. 15, 2018) MER-B took a Pancam of the Martian sunrise.


5000 sols on Mars

On February 16, 2018, MER-B achieved 5000 sols (Martian Days) on Mars since landing on the planet in January 2004. At the time it was making its way down Perseverance Valley (aka the Gully) on the western rim of Endeavour crater, which it has been exploring in since 2011. The interior rim of the crater where ''Opportunity'' is exploring is sloped at about 15 to 20 degrees on average.


=Sol 5,000 (Feb. 16, 2018)

= On Sol 5000 the team used the rover to take a self-portrait including the Pancam mast, by using the microscopic imager on the end of the robotic arm. Power production on Sol 5004 (Feb. 20, 2018) was 653 watt-hours.


Dust storm

In June 2018, a local dust storm began to develop near ''Opportunity''. The first signs of the distant storm were discovered on June 1, 2018, in photographs by the
Mars Color Imager The Mars Color Imager (MARCI) is a wide-angle, relatively low-resolution camera built for ''Mars Climate Orbiter'' and ''Mars Reconnaissance Orbiter''. MARCI views the surface of Mars in five visible and two ultraviolet bands. Each day, MARCI coll ...
(MARCI) camera on the
Mars Reconnaissance Orbiter The ''Mars Reconnaissance Orbiter'' (''MRO'') is a spacecraft designed to search for the existence of water on Mars and provide support for missions to Mars, as part of NASA's Mars Exploration Program. It was launched from Cape Canaveral on Au ...
(MRO). More weather reports from the MRO and the MARCI team indicated a prolonged storm. Although this was, at that time, still far away from the rover, it began to influence the atmospheric opacity at the rover's location. Within days, the storm had spread globally. As a result, plans were developed on June 4 and 5 to prepare for the anticipated lower power supply. Since then, the atmosphere over the rover had worsened further. On June 3, the 5105th Sol, ''Opportunity'' solar panels still generated 468 watt-hours. The atmospheric opacity (called tau value) was about 1.0. The power supply dropped to 345 watt hours on June 4 at a tau of 2.1. On June 6, only 133 watt hours were generated, the tau value was estimated at 3.0. ''Opportunity'' has not experienced such high tau levels since the last dust storm in 2007, which had an estimated tau value of 5.5. The 2018 storm had an estimated tau value of 10.8 on June 10 and the storm spanned an area of - the approximate area of both North America and Russia combined. The rover team made another plan, in which the rover gets only the latest commands at the first sol in the morning and sleeps until the next morning. The rover then wakes up in the afternoon to conduct atmospheric measurements with the Pancam and conduct a brief communication session with the MRO orbiter. However, scientific investigations were discontinued, and the rover entered continuous hibernation on June 12. Although ''Opportunity'' rover requires the power generated by solar panels to keep the central electrical components warm, it features a small
radioisotope heater unit A radioisotope heater unit (RHU) is a small device that provides heat through radioactive decay. They are similar to tiny radioisotope thermoelectric generators (RTG) and normally provide about one watt of heat each, derived from the decay of ...
(RPU) that does not require sunlight to function,Mars Opportunity: Rover 'should ride out storm'
Jonathan Amos, ''BBC News''. 14 June 2018.
and the relatively warm summer weather was not expected to damage the electronic components at night. The winter cold is likely the reason that ''Opportunity'' twin rover ''Spirit'' stopped working in 2010. Although such dust storms are not surprising, they rarely occur. They can arise within a short time and then persist for weeks to months. During the southern season of summer, the sunlight heats dust particles and brings them higher into the atmosphere. This creates wind, which in turn stirs up more dust. This results in a feedback loop that scientists are still trying to understand, so they are taking an opportunity to study this storm from orbit using the various visible and infrared instruments on the MRO orbiter. As of June 10, 2018 the mission for ''Opportunity'' was able to extend its 92-day (Earth) mission to over 5250 days. ''Opportunity'' took its last image (of an overall total of 228,771 raw images) on June 10, 2018. On June 12, 2018, ''Opportunity'' entered
safe mode Safe mode is a diagnosis, diagnostic mode of a computer operating system (OS). It can also refer to a mode of operation by application software. ''Safe mode'' is intended to help fix most, if not all, problems within an operating system. It is a ...
as evidenced by its lack of communication. A NASA teleconference about the
dust storm A dust storm, also called a sandstorm, is a meteorological phenomenon common in arid and semi-arid regions. Dust storms arise when a gust front or other strong wind blows loose sand and dirt from a dry surface. Fine particles are transpo ...
was presented on June 13, 2018. ''Opportunity'' team implemented additional communication times from NASA's Deep Space Network to receive up-to-date data from Mars. The data obtained showed that the temperature of the rover had fallen to . An advantage of the dust storm is that the temperature differences are not as extreme as they are on the surface of Mars. In addition, the swirled-up dust absorbs heat, thereby increasing the ambient temperature at the location of ''Opportunity''.


After the storm

At the beginning of September 2018, the atmospheric opacity (tau) over the rover site was estimated to be below 1.5. This started a 45-day window that was expected to be the best time to re-establish contact with the rover. After more than three months without contact, NASA expected ''Opportunity'' to have most of its timers in fault state. To take this into account, as of September 19, 2018, "sweep and beep" commands are sent throughout the available transmission time. By early October, the storm subsided and the atmosphere cleared up, but the rover kept silent, suggesting either a catastrophic failure or a layer of dust covered its solar panels. By November 27, 2018, NASA had attempted to contact ''Opportunity'' 359 times. The team remained hopeful that a windy period between November 2018 and January 2019 would clear the dust from its solar panels, as had happened before.


2019

On February 12, 2019, NASA announced it made its final attempt to contact the rover before declaring the rover dead.


Sol milestones

*Sol 3,000 (July 2, 2012) *Sol 4,000 (April 26, 2015) *Sol 5,000 (February 16, 2018) *Sol 5,111 (June 10, 2018) – Contact lost. *Sol 5,352 (Feb 12, 2019) – Mission officially declared complete.


Solar array energy production


Examples

Examples of watt-hours per sol collected by the rover:


Craters, rocks, etc.

Some of the craters MER-B has investigated * Eagle crater, visited 2004, across (diameter) * Endurance crater, 2004, across **Burn's Cliff *
Victoria crater Victoria is an impact crater on Mars located at 2.05°S, 5.50°W in the Meridiani Planum extraterrestrial plain, lying situated within the Margaritifer Sinus quadrangle (MC-19) region of the planet Mars. This crater was first visited by the Mars E ...
, 2006–9, 800 meters (half a mile) across. **
Cape Verde Cape Verde or Cabo Verde, officially the Republic of Cabo Verde, is an island country and archipelagic state of West Africa in the central Atlantic Ocean, consisting of ten volcanic islands with a combined land area of about . These islands ...
*
Endeavour crater Endeavour is an impact crater located in the Meridiani Planum extraterrestrial plain within the Margaritifer Sinus quadrangle (MC-19) region of the planet Mars. Endeavour is about in diameter. Using ''Mars Reconnaissance Orbiter'' data, phy ...
, since 2011, ** Cape York ** Solander Point, 2013 **
Cape Tribulation Cape Tribulation is a headland and coastal locality in the Shire of Douglas in northern Queensland, Australia. In the , Cape Tribulation had a population of 123 people. Geography The locality is north of Cairns. It is within the Daintree N ...
***Marathon Valley, 2015-2016 **Perseverance Valley (aka the Gully), 2017-2018


Rocks

Some excitement from finding meteorites, new types of rock or signatures detected from orbit, and speculations on ancient alien fossils which as of yet lean towards geological processes. ''Examples'' *
Block Island Block Island is an island of the Outer Lands coastal archipelago in New England, located approximately south of mainland Rhode Island and east of Long Island's Montauk Point. The island is coterminous with the town of New Shoreham, Rhode Isl ...
*
Bounce Rock Bounce Rock is a football-sized primarily pyroxene rock found within the Meridiani Planum of the planet Mars. It was discovered and observed by the Mars Exploration Rover '' Opportunity'' in April 2004. The rock was named for it having been stru ...
*
El Capitan El Capitan (; ) is a vertical Rock formations in the United States, rock formation in Yosemite National Park, on the north side of Yosemite Valley, near its western end. The El Capitan Granite, granite monolith is about from base to summit alo ...
*
Heat Shield Rock Heat Shield Rock is a basketball-sized iron-nickel meteorite found on the Meridiani Planum plain of Mars by the Mars rover ''Opportunity'' in January 2005. Informally referred to as "Heat Shield Rock" by the Opportunity research team, the met ...
(formally the Meridiani Planum meteorite) * Last Chance *
Mackinac Island Mackinac Island ( , ; ; ; ) is an island and resort area, covering in land area, in the U.S. state of Michigan. The name of the island in Odawa is Michilimackinac and "Mitchimakinak" in Ojibwemowin, meaning "Great Turtle". It is located in ...
* Oileán Ruaidh * Shelter Island *Jelly Doughnut (aka Pinnacle Island) Some other famous targets are the "blueberries" (2004) and "newberries", aka Kirkwood spheres (2012) See also List of rocks on Mars#Opportunity and List of surface features of Mars imaged by ''Opportunity''


Images

The rover could take pictures with its different cameras, but only the PanCam camera had the ability to photograph a scene with different color filters. The panorama views are usually built up from PanCam images. By February 3, 2018, ''Opportunity'' had returned 224,642 pictures.


Views


Panoramas

A selection of panoramas from the mission:


Close-up images


From orbit


Area maps


Traverse maps

An example of a rover traverse map featuring a line showing path of the rover, and mission sols, which are Mars days counted from its landing and typical of Mars surface mission time reporting. Topographic lines and various feature names are also common.


See also

* ''Curiosity'' rover timeline * ''
InSight Insight is the understanding of a specific causality, cause and effect within a particular context. The term insight can have several related meanings: *a piece of information *the act or result of understanding the inner nature of things or of se ...
'' * ''
Mars Express ''Mars Express'' is a space exploration mission by the European Space Agency, European Space Agency (ESA) exploring the planet Mars and its moons since 2003, and the first planetary mission attempted by ESA. ''Mars Express'' consisted of two ...
'' * ''Perseverance'' rover timeline * ''Sojourner'' rover timeline * ''Spirit'' rover timeline


References


External links


NASA/JPL Mission page


{{Mars spacecraft +
Opportunity Opportunity may refer to: Places * Opportunity, Montana, an unincorporated community, United States * Opportunity, Nebraska, an unincorporated community, United States * Opportunity, Washington, a former census-designated place, United States * ...
Opportunity Opportunity may refer to: Places * Opportunity, Montana, an unincorporated community, United States * Opportunity, Nebraska, an unincorporated community, United States * Opportunity, Washington, a former census-designated place, United States * ...
Exploration of Mars