Allan Hills 77005 (also known as Allan Hills A77005, ALHA77005, ALH77005 and ALH-77005
) is a
Martian meteorite that was found in the
Allan Hills
The Allan Hills () are a group of hills, mainly ice free and about long, lying just north-west of the Coombs Hills near the heads of Mawson Glacier and Mackay Glacier in the Oates Land and Victoria Land regions of Antarctica.
Exploration and n ...
of
Antarctica
Antarctica () is Earth's southernmost and least-populated continent. Situated almost entirely south of the Antarctic Circle and surrounded by the Southern Ocean (also known as the Antarctic Ocean), it contains the geographic South Pole. ...
in 1977 by a
Japanese National Institute of Polar Research mission team and
ANSMET.
Like other members of the group of
SNCs (
shergottite,
nakhlite,
chassignite), ALH-77005 is thought to be from
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 ...
.
Description
On discovery, the
mass
Mass is an Intrinsic and extrinsic properties, intrinsic property of a physical body, body. It was traditionally believed to be related to the physical quantity, quantity of matter in a body, until the discovery of the atom and particle physi ...
of ALH-77005 was . Initial geological examination determined that the meteorite was composed of ~55%
olivine
The mineral olivine () is a magnesium iron Silicate minerals, silicate with the chemical formula . It is a type of Nesosilicates, nesosilicate or orthosilicate. The primary component of the Earth's upper mantle (Earth), upper mantle, it is a com ...
, ~35%
pyroxene
The pyroxenes (commonly abbreviated Px) are a group of important rock-forming inosilicate minerals found in many igneous and metamorphic rocks. Pyroxenes have the general formula , where X represents ions of calcium (Ca), sodium (Na), iron ( ...
, ~8%
maskelynite and ~2% opaques.
In March 2019, researchers reported the possibility of
biosignature
A biosignature (sometimes called chemical fossil or molecular fossil) is any substance – such as an element, isotope, molecule, or phenomenon – that provides scientific evidence of past or present life on a planet. Measurable ...
s in this
Martian meteorite based on its microtexture and morphology as detected with
optical microscopy
Optics is the branch of physics that studies the behaviour and properties of light, including its interactions with matter and the construction of instruments that use or detect it. Optics usually describes the behaviour of visible, ultravio ...
and
FTIR-ATR microscopy, and on the detection of mineralized
organic compound
Some chemical authorities define an organic compound as a chemical compound that contains a carbon–hydrogen or carbon–carbon bond; others consider an organic compound to be any chemical compound that contains carbon. For example, carbon-co ...
s,
suggesting that
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 ...
could have existed on the planet Mars.
More broadly, and as a result of their studies, the researchers suggest
Solar System
The Solar SystemCapitalization of the name varies. The International Astronomical Union, the authoritative body regarding astronomical nomenclature, specifies capitalizing the names of all individual astronomical objects but uses mixed "Sola ...
materials should be carefully studied to determine whether there may be signs of
microbial forms within other
space rocks as well.
See also
*
Allan Hills 84001
*
Glossary of meteoritics
*
History of Mars observation
*
Life on Mars
The possibility of life on Mars is a subject of interest in astrobiology due to the planet's proximity and similarities to Earth. To date, no conclusive evidence of past or present life has been found on Mars. Cumulative evidence suggests that ...
*
List of Martian meteorites on Earth
*
List of meteorites on Mars
*
Nakhla meteorite
*
Mars sample return mission
*
Panspermia
Panspermia () is the hypothesis that life exists throughout the universe, distributed by space dust, meteoroids, asteroids, comets, and planetoids, as well as by spacecraft carrying unintended contamination by microorganisms,Forward planetary c ...
*
Shergotty meteorite
*
Water on Mars
Although very small amounts of liquid water may occur transiently on the surface of Mars, limited to traces of dissolved moisture from the atmosphere and thin films, large quantities of ice are present on and under the surface. Small amounts of ...
References
Further reading
*
External links
Meteoritical SocietyThe British and Irish Meteorite SocietyThe Natural History Museum's meteorite catalogue database
{{Portal bar, Astronomy, Biology, Solar System
Astrobiology
Martian meteorites
Meteorites found in Antarctica