Isidis Planitia is a plain located within a giant

impact basin An impact crater is a circular depression in the surface of a solid astronomical object formed by the hypervelocity impact of a smaller object. In contrast to volcanic craters, which result from explosion or internal collapse, impact craters ...

Mars Mars is the fourth planet from the Sun and the second-smallest planet in the Solar System, only being larger than Mercury. In the English language, Mars is named for the Roman god of war. Mars is a terrestrial planet with a thin atmos ...

, located partly in the

Syrtis Major quadrangle The Syrtis Major quadrangle is one of a series of 30 quadrangle maps of Mars used by the United States Geological Survey (USGS) Astrogeology Research Program. The Syrtis Major quadrangle is also referred to as MC-13 (Mars Chart-13). The quadr ...

and partly in the

Amenthes quadrangle The Amenthes quadrangle is one of a series of 30 quadrangle maps of Mars used by the United States Geological Survey (USGS) Astrogeology Research Program. The Amenthes quadrangle is also referred to as MC-14 (Mars Chart-14). The quadrangle ...

. At approximately in diameter, it is the third-largest obvious impact structure on the planet, after the

Hellas Hellas may refer to: Places in Greece *Ἑλλάς (''Ellás''), genitive Ἑλλάδος (''Elládos''), an ancient Greek toponym used to refer to: ** Greece Greece,, or , romanized: ', officially the Hellenic Republic, is a country i ...

and

Argyre Chryse and Argyre ( and ) were a pair of legendary islands, located in the Indian Ocean and said to be made of gold (''chrysos'' in Greek) and silver (''argyros''). In Book 6, chapter 23 of his '' Natural History'', concerning the regions near ...

basins. Isidis was likely the last major basin to be formed on Mars, having formed approximately 3.9 billion years ago during the

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. Due to dust coverage, it typically appears bright in telescopic views, and was mapped as a classical

albedo feature An albedo feature is a large area on the surface of a planet (or other Solar System body) which shows a contrast in brightness or darkness (albedo) with adjacent areas. Historically, albedo features were the first (and usually only) features to b ...

, Isidis Regio, visible by

telescope A telescope is a device used to observe distant objects by their emission, absorption, or reflection of electromagnetic radiation. Originally meaning only an optical instrument using lenses, curved mirrors, or a combination of both to obse ...

in the pre-spacecraft era. A study reported in ''

Icarus In Greek mythology, Icarus (; grc, Ἴκαρος, Íkaros, ) was the son of the master craftsman Daedalus, the architect of the labyrinth of Crete. After Theseus, king of Athens and enemy of Minos, escaped from the labyrinth, King Minos sus ...

'' described the complex geologic history of parts of Isidis, especially areas near the

Deuteronilus Deuteronilus Mensae is a region on Mars 937 km across and centered at . It covers 344°–325° West and 40°–48° North. Deuteronilus region lies just to the north of Arabia Terra and is included in the Ismenius Lacus quadrangle. It is a ...

contact. This contact is the supposed edge of a vast

Martian ocean The Mars ocean hypothesis states that nearly a third of the surface of Mars was covered by an ocean of liquid water early in the planet's geologic history. This primordial ocean, dubbed Paleo-Ocean and Oceanus Borealis , would have filled the ...

. The researchers found evidence of a Late Hesperian/Early Amazonian Sea in the area. The sea would have quickly frozen over.

Esker An esker, eskar, eschar, or os, sometimes called an ''asar'', ''osar'', or ''serpent kame'', is a long, winding ridge of stratified sand and gravel, examples of which occur in glaciated and formerly glaciated regions of Europe and North Ame ...

s formed under the ice. Just to the west of Isidis is

Syrtis Major Planum Syrtis Major Planum is a "dark spot" (an albedo feature) located in the boundary between the northern lowlands and southern highlands of Mars just west of the impact basin Isidis in the Syrtis Major quadrangle. It was discovered, on the basi ...

, a low-relief

shield volcano A shield volcano is a type of volcano named for its low profile, resembling a warrior's shield lying on the ground. It is formed by the eruption of highly fluid (low viscosity) lava, which travels farther and forms thinner flows than the more v ...

that is a prominent dark albedo feature of Mars, which formed after the basin. The westernmost extent is bounded by a subregion,

Northeast Syrtis Northeast Syrtis is a region of Mars once considered by NASA as a landing site for the Mars 2020 rover mission. This landing site failed in the competition with Jezero crater, another landing site dozens of kilometers away from Northeast Syrtis. ...

with diverse geology. Around the Isidis basin

magnesium carbonate Magnesium carbonate, (archaic name magnesia alba), is an inorganic salt that is a colourless or white solid. Several hydrated and basic forms of magnesium carbonate also exist as minerals. Forms The most common magnesium carbonate forms are ...

was found by the ''

Mars Reconnaissance Orbiter ''Mars Reconnaissance Orbiter'' (MRO) is a spacecraft designed to study the geology and climate of Mars, provide reconnaissance of future landing sites, and relay data from surface missions back to Earth. It was launched on August 12, 2005, a ...

''. This mineral indicates that water was present and that it was not acidic, pH conditions more favorable for the evolution of life. The name ''Isidis Planitia'' follows the earlier name ''Isidis Regio'' ('region of Isis').

Isis Isis (; ''Ēse''; ; Meroitic language, Meroitic: ''Wos'' 'a''or ''Wusa''; Phoenician language, Phoenician: 𐤀𐤎, romanized: ʾs) was a major ancient Egyptian deities, goddess in ancient Egyptian religion whose worship spread throughou ...

is the

Egyptian goddess Ancient Egyptian deities are the gods and goddesses worshipped in ancient Egypt. The beliefs and rituals surrounding these gods formed the core of ancient Egyptian religion, which emerged sometime in prehistory. Deities represented natural f ...

heaven Heaven or the heavens, is a common religious cosmological or transcendent supernatural place where beings such as deities, angels, souls, saints, or venerated ancestors are said to originate, be enthroned, or reside. According to the bel ...

and

fertility Fertility is the capability to produce offspring through reproduction following the onset of sexual maturity. The fertility rate is the average number of children born by a female during her lifetime and is quantified demographically. Ferti ...

Gallery

Wikiarabiaboundaries.jpg, MOLA map showing boundaries of Isidis Planitia and other regions Syrtis-Isidis zoom 64 pano.jpg, MOLA colorized topographic map showing Isidis Planitia (right) and the adjacent low-relief shield volcano

(left).

Beagle 2

The

Beagle 2 The ''Beagle 2'' is an inoperative British Mars lander that was transported by the European Space Agency's 2003 ''Mars Express'' mission. It was intended to conduct an astrobiology mission that would have looked for evidence of past life on Ma ...

lander was about to land in the eastern part of Isidis Planitia in December 2003, when contact with the craft was lost. In January 2015, NASA reported the Beagle 2 had been found on the surface in Isidis Planitia (location is about ). High-resolution images captured by the

identified the lost probe, which appears to be intact. ( see discovery images here)

Mars 2020 mission

In 2018 the

Jezero (crater) Jezero is a crater on Mars in the Syrtis Major quadrangle, about in diameter. Thought to have once been flooded with water, the crater contains a fan- delta deposit rich in clays. The lake in the crater was present when valley networks were f ...

in the north west rim of the Isidis basin was selected as a landing site for the

Mars 2020 Mars 2020 is a Mars rover mission forming part of NASA's Mars Exploration Program that includes the rover '' Perseverance'', the small robotic, coaxial helicopter '' Ingenuity'', and associated delivery vehicles. Mars 2020 was launched from ...

mission, including the

Perseverance rover ''Perseverance'', nicknamed ''Percy'', is a car-sized Mars rover designed to explore the Jezero crater on Mars as part of NASA's Mars 2020 mission. It was manufactured by the Jet Propulsion Laboratory and launched on July 30, 2020, at 11:50 ...

Interactive Mars map

References

External links