Quoted from the page popsci.comThe discovery of this new molecule dates back to 2017, when the Curiosity rover collected soil samples from Mars’ Bagnold Dune. At that time, this spacecraft suffered an unexpected malfunction: the drill suddenly malfunctioned.
Instead of aborting the mission, NASA scientists changed the sampling technique in such a way that the rover placed the dirt sample into a cup containing a chemical cocktail instead of an empty cup. Surprisingly, this type of sampling—known as experimental wet sampling—helps scientists identify organic molecules that have never been seen on Mars.
The Curiosity rover has been searching for biosignatures, or indicators of previous life on Mars, since landing on the red planet in 2012. Today, Mars is mostly made up of dirt, dust and gas, but there may have been lakes, rivers and microbial life in the past.
The Curiosity sample collected from the Bagnold Dune on Mars lacks biosignatures, which are evidence of past life. However, it has organic molecules never seen before on this planet, namely ammonia and benzoic acid. (Read also; Bacteria sent to Mars to fuel space shuttle rockets )
These organic molecules are good indicators of biosignatures, as they are chemicals that may have come from past life on Mars. Moreover, the discovery of this chemical also shows that the sample collection method is promising. The wet chemistry experiments carried out by the NASA team were published in the journal Nature Astronomy.
Organic matter, including thiophene, benzene, toluene, and small carbon chains has previously been found on Mars from sediment samples. These past compounds were discovered using Curiosity’s special oven that worked to heat the sediment and release these molecules.
Ammonia and benzoic acid have never been discovered before by this method. In a wet experiment, Curiosity dumped impurities into a mixture of chemical reagents that set off a chemical reaction that allowed the researchers, back in the lab, to find out what molecules were present.
Researchers still need to figure out where and how exactly these molecules appeared. The study suggests that the molecule could originate from geological processes on the planet, but could also potentially be an indicator of past habitability. (Read also; NASA explorers find evidence that Mars used to be like Earth )
The dune where samples were collected is in Gale Crater. Places on Mars that were previously thought to have been filled with water. This place is suitable for looking for signs of previous life. Researchers are awaiting the launch of the European Space Agency’s ExoMars expedition to get more samples to work with.
The discovery of this new molecule helps to provide a clearer understanding of the history of Mars. Because, little by little, scientists continue to uncover the secrets that are kept on this Red Planet.
(Web)
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