Scientists can backtrack the history of Mars by analyzing the chemical elements of the materials from the planet. Several clues indicate that Mars once had water. The evidence for this is salty surfaces, riverbeds, and ancient shorelines. They have also drilled the rocks to study their organic composition. Their discoveries motivate them to continue exploring for signs of life.
The research inside Curiosity called Sample Analysis at Mars (SAM) shows that some minerals in rocks at Gale Crater are likely a product of an ice-covered lake. The team thinks that the fossils have been accumulating when Mars was turning cold.
Curiosity’s target of Gale crater as a docking site is because it has hints of previous water like clay deposits. Curiosity has observed layers of sediments, which is a sign of deposition in ancient lakes. There is evidence that the residues are a product of incredible water-flowing and the cold icy conditions.
Heather Franz, a NASA geochemist, says that there is evidence that Mars’s surroundings might have been shifting from warm and humid to cool and dry. Franz adds that the changes in Mars are also because of the shift from volcanic activity to coldness. All the same, the data seems to indicate that rocks are proof of Martian climate change.
Curiosity team’s findings show the presence of carbon dioxide and oxygen from the Martian samples. These gases are essential for proving the existence of life on the planet. Scientists are trying to understand the carbon cycle on Mars. Paul Mahaffy, the principal investigator on SAM, says that the study of the carbon cycle on Mars reveals more about the climate of Mars.
The Curiosity team usually heats the rock samples in an oven to about 800 degrees Celcius. The gas generation is indicative of the type of gas in the rock samples. In this case, the gases were carbon dioxide and oxygen, a sign of carbon cycling.
Studies show that the ancient Martian atmosphere was mainly carbon dioxide, most of which embeds in rocks as carbonates. Scientists think that carbon dioxide may have been absorbed in oceans then embedded in rocks. Franz and her colleagues argue that the carbon storage form on Mars is as oxalates since the rock samples require high temperatures to release the gases. The process of oxalate formation is abiotic photosynthesis.
In conclusion, Franz and her colleagues hope to obtain more soil and dust from random places on Mars to understand if the carbon on Mars is storable as oxalates. They will be able to get the samples from Jezero Crater when the Perseverance Mars rover lands on Mars. They will test the samples when they return to earth.