Derek Ward-Thompson and Megan Argo: Nasa’s Curiosity Mars Rover has found the largest organic (carbon-containing) molecules ever on the red planet. The discovery is one of the most important findings in the search for proof of the past living on Mars.
This is because, at least on earth, relatively complex carbon molecules with long chains are involved in biology. These molecules can actually be fragments of fatty acids that are found in the membranes around organic cells, for example.
Scientists think that if life ever came to Mars, it was probably microbial in nature. Because microbes are so small, it is difficult to be definitive about possible evidence for life on Mars. Such evidence needs more powerful scientific instruments that are too large to be put on a robber.
The organic molecules found by curiosity consists of carbon atoms coupled in long chains, with other elements that are bound to them, such as hydrogen and oxygen. They come from a 3.7 million-year-old rock called Cumberland, met by the Rover at an assumed dried-up lake in Mars’ Gale Crater. Scientists used the sample analysis at Mars (SAM) instrument on NASA Rover to make their discovery.
Scientists were actually looking for proof of amino acids, the building blocks of proteins and therefore important components of life as we know them. But this unexpected finding is almost as exciting. The research is published in Proceedings of the National Academies of Science.
Among the molecules, dean, which has 10 carbon atoms and 22 hydrogen atoms and dodecan, with 12 carbon atoms and 26 hydrogen atoms. These are known as alkanes, which fall under the umbrella of the chemical compounds that are known as hydrocarbons.
It is an exciting time in the search for life on Mars. In March of this year, scientists presented proof of characteristics in another rock that were sampled on Mars on Mars elsewhere by the perseverance.
These characteristics, called “Leopard Spots” and “Poppy Seeds”, could have been produced by the functioning of microbial life in the distant past, or not. The findings were presented at an American conference and have not yet been published in a Peer Reviewed Journal.
The Mars Sample Return Mission, a collaboration between NASA and the European Space Agency, offers hope that samples of rock collected and stored by perseverance can be brought to earth for study in laboratories.
The powerful instruments that are available in terrestrial laboratories can finally confirm whether or not there is clear evidence for the past living on Mars. In 2023, however, an independent assessment council criticized the increase in the budget of Mars Sample Return.
This led the agencies to reconsider how the mission could be implemented. They are currently studying two revised options.
Signs of life?
Cumberland was found in a Gale Crater region called Yellowknife Bay. This area contains rock formations that resemble those formed when sediment builds up on the bottom of a lake.
One of the scientific goals of Curiosity is to investigate that previous circumstances would have been suitable for the development of life, so an old lacquer bed is the perfect place to look for them.
The researchers think that the alkane molecules may have been components of more complex fatty acid molecules. On earth, fatty acids are components of fats and oils.
They are produced by biological activity in processes that help form cell membranes, for example. The proposed presence of fatty acids in this rock monster has been around for several years, but the new paper describes full proof.
Fatty acids are long, linear hydrocarbon molecules with a carboxyl group (COOH) on one side and a methyl group (CH3) on the other, which form a chain of carbon and hydrogen atoms.
A fat molecule consists of two main components: glycerol and fatty acids. Glycerol is an alcohol molecule with three carbon atoms, five hydrochens and three hydroxyl (chemically bound oxygen and hydrogen, oh) groups. Fatty acids can have 4-36 carbon atoms; However, most of them have 12-18. The longest carbon chains in Cumberland are 12 atoms long.
Organic molecules saved in old Martian rots offer a critical state of service in the habitability of Mars in the past and can be chemical biosa signatures (signs that life once was there).
The Monster of Cumberland has been analyzed by the SAM instrument many times, with the help of various experimental techniques, and has demonstrated evidence of clay minerals, as well as the first (smaller and simpler) organic molecules found on Mars, in 2015.
These include different classes chlorated and sulfur-containing organic compounds in Gale crater-sedimentary rocks, with chemical structures of up to six carbon atoms. The new discovery doubles the number of carbon atoms found in a single molecule on Mars.
The alkaan molecules are important in the search for biosa signatures on Mars, but how they actually formed remains unclear. They can also be derived by geological or other chemical mechanisms that do not concern fatty acids or life. These are known as abiotic sources.
The fact that they exist today in monsters that have been exposed to a harsh environment for many millions of years, gives astrobiologists (scientists who study the possibility of life outside the earth) hopes that nowadays the proof of old life can still be detectable.
It is possible that the sample even contains organic molecules with a longer chain. It can also contain more complex molecules that are indicative of life, rather than geological processes.
Unfortunately, Sam is unable to detect it, so the next step is to deliver Martian Rock and Soil to more capable laboratories on the earth. Mars Sample Return would do this with the samples that have already been collected by the perseverance Mars Rover. The only thing that is needed now is the budget.
Derek Ward-Thompson, professor of astrophysics, University of Central Lancashire and Megan Argo, senior teacher Astronomy, University of Central Lancashire
This article has been re -published from The conversation Under a Creative Commons license. Read the Original article.
