We've found over a hundred precious Mars rocks that have traveled from the red planet and landed on Earth. One of the most enigmatic specimen is ALH84001.
The piece of meteorite was picked up by a snowmobile in the ice field of Alan Hills in Antarctica in 1984 and is thought to have formed on Mars around 4 billion years ago. It was the most unusual rock collected on the trip.
Scientists are intrigued by the minuscule traces of organic carbon detected as part of the rock's composition. Is this proof that alien life existed on Mars billions of years ago?
According to the latest study, it's probably not. The organic molecule found in the meteorite are most likely the result of fluid and rock interactions similar to those on Earth.
The meteorite was from Allan Hills. The scholl and the university are associated with NASA.
"Analyzing the origin of the meteorite's minerals can be a window to reveal both the geochemical processes occurring early in Earth's history and Mars' potential for habitability," says Andrew Steele, from the Carnegie Institution for Science in Washington DC.
The team notes in their paper that ALH84001 is one of the oldest known rocks from Mars and may have been involved in early planetary processes.
The provenance and formation mechanisms of these organics include abiotic production by impact-related, igneous, and/or hydrothermal processes.
The team gained access to a thin section and a chip of the meteorite, obtained from NASA Johnson Space Center.
They used a variety of techniques to analyze the fragments, including using light to study the chemical composition of matter.
The characteristics of the rock show that it could have been formed in the presence of non-biological processes that produce organic carbon molecule here on Earth. The first one is serpentinization, which happens when molten lava and magnesium-rich rocks interact with water and produce hydrogen.
The second process is called carbonation, where rocks react with slightly acidic water that has dissolved carbon dioxide in it, resulting in carbonate materials. It's not clear if both processes happened at the same time, but the study suggests they weren't happening for a long time.
Steele says that all that is required for this type of organic synthesis is a brine with dissolved carbon dioxide.
"These geological reactions are responsible for a pool of organic carbon compounds from which life could have evolved and represent a background signal that must be taken into consideration when searching for evidence of past life on Mars."
The presence of organic material in the meteorite has led to several other abiotic processes being suggested, including volcanic activity, impact events on Mars, and the possibility that the meteorite is contaminated with alien life.
Serpentinization and carbonation are rare in Martian meteorites, although they have been detected through surveys of the red planet. It seems that the abiotic synthesis of organic molecule has been happening on Mars for a long time.
These reactions are responsible for abiotic organic synthesis, methane production, and mineralogical diversity on Earth. The team concludes in their paper that the presence of methane in the atmosphere on Mars is explained by reactions relevant to habitability.
There are implications for Earth as well as for Mars, which had similar beginnings. One of the ways in which these new findings will be useful in the future is to inform research into the ancient history of our own planet.
Steele says that if these reactions happened on ancient Mars, they must have happened on ancient Earth, and that could explain the results from Enceladus as well.
The search for life on Mars is more than just an attempt to answer the question. It addresses the question of where we came from.
The research has been published.
All Rights Reserved © 2024
