Is there life on Mars? To answer this question, scientists around the world have been exploring it for decades.
Recently, NASA’s curiosity Rover discovered new organic molecules in the dry soil near Mars’ Gail crater, which excited scientists because these organic molecules have different biological origins.
These organic molecules were extracted by curiosity from mudstone faults on the surface of Mars. After analysis, a large number of thiophene aromatic compounds were found in this group of Martian soil samples.
On earth, this kind of compound usually exists in crude oil (organisms that die due to extrusion and overheating). It is formed by the reaction of sulfur and organic hydrocarbons at temperatures higher than 120 ℃. Hydrocarbons and sulfur have clear biological sources.
Therefore, researchers are currently studying the formation pathway of thiophene on Mars and analyzing whether it is involved in life activities.
Several biological pathways for thiophene have been identified, which appear to be more likely than chemical pathways, said Dirk Schultz markucci, an Astrobiologist at Washington State University after the analysis.
Although thiophene can appear on Mars in many ways, for example, thiophene has been detected in meteorites. In addition, geological processes will also provide heat for the formation of thiophene, and sulfur will be produced in volcanic activities on Mars.
However, these methods require that sulfur is nucleophilic, that is, sulfur atoms can give electronic bonds. However, there is another possibility that sulfur on Mars basically exists in the form of non nucleophilic sulfate – biological sulfate reduction (BSR).
Of course, if thiophene appears on Mars in this way, it can be inferred that there is life on Mars. Based on this, researchers speculate that Mars is warmer than it was about 3 billion years ago today, because Mars is rich in water resources.
When the climate is humid and thiophene is produced, bacterial colonies already exist. When Mars dries, the thiophene produced will remain in the soil until today’s curiosity probe discovered it.
Unfortunately, the curiosity Rover uses pyrolytic analysis to heat Martian soil samples above 500 ℃, so the information we get from it is limited.
However, the Rosalind Franklin rover, originally scheduled for launch in July 2020, will be equipped with milder analytical instruments, and we will be able to obtain more valuable information by then.
For example, carbon and sulfur isotope information can show biological possibilities. Schultz markucci said that extraordinary discoveries require extraordinary means. If one day man can land on Mars, everything will be revealed.