The rocks can preserve organic molecules for millions and, in the case of Marteif there was life one day, his firm could be found in the stones. Still far from confirming that possibility, a group of researchers has detected the longest organic molecules found to date.
An investigation in which the Astrobiology Center of Spain has participated and headed by the French National Center for Scientific Research (CNRS) accounts for the detection of these molecules in a sample of lutita (a type of sedimentary rock) found in the Gale Crater of Mars.
The origin of these molecules “remains uncertain, since they could come from abiotic or biological sources,” the authors write in a study published by PNAS.
The detection was carried out by the Sam instrument (Analysis of samples on Mars) that has on board the NASA Curiosity Rover, which had already previously identified organic compounds in samples of sedimentary rocks with chemical structures containing up to six carbon atoms.
In the Lulita sample on which the study is based have already been detected isotopic sulfur and carbon anomalies and a great abundance of nitrates.
The new study informs of the detection of a series of compounds (formed by carbon and hydrogen) LINEARLA LARG, specifically, the Dean (C10H22), Undecano (C11H24) and DODECANO (C12H26).
These long carbon chains, which contain up to 12 consecutive carbon atomsThey could have similar characteristics to fatty acids produced on Earth by biological activity, according to CNRS.
The absence of geological movements and the cold and arid climate of Mars have allowed to preserve that organic matter in a clay rich for 3.7 billion years, that is, the time when life appeared on earth.
Laboratory experiments support the hypothesis that the alleged alkanes were originally preserved in lutita as long chain carboxylic acids, the authors point out and note that “the origin of these molecules remains uncertain, since they could come from abiotic or biological sources.”
The organic molecules preserved in old Martian rocks constitute a critical record of the past habitability of that planet and could be chemical biofirms.
This new finding paves the road, indicates the CNRS, for future interplanetary scientific missions in search of complex chemistry traces close to life, which will be one of the objectives of Exomars, which the European Space Agency (ESA) will launch in 2028.