Scientists have long assumed that Mars may have once been home to primitive forms of life. They believe that during the Noachian and Hesperian Periods of Martian history between three and four billion years ago, the Red planet’s surface was abundant in water, which could have supported life.
A new study led by Dr. Sean McMahon, from the University of Edinburgh in the U.K. and Yale University in Connecticut, claims that ancient microbial life could still be preserved in certain types of rocks on Mars. The research team has compiled a field guide which could be beneficial for the upcoming space missions to the planet, pinpointing exactly where the missions could search for traces of tiny creatures known as microbes.
For the purpose of the study, the research team reviewed studies of fossils on Earth and assessed the results of lab experiments that replicated Martian conditions to search for the most promising sites on Mars to explore for traces of ancient life.
McMahon’s team found that the best place to search for fossils are sedimentary rocks formed on the floor of ancient Martian lakes. The sedimentary rocks made of compacted mud or clay are the most likely to contain fossils. The research team claims that these types of Martian rocks are rich in iron and mineral called silica, which helps preserve fossils.
Notably, Mars is not subject to plate tectonics which over time tends to destroy rocks and fossils inside them. This suggests that the ancient sedimentary rocks are still better preserved.
The researchers are hopeful that the latest study will help NASA in choosing a landing site for its impending Mars 2020 mission, which is tasked with finding signs of past life on Mars. The US space agency’s Mars 2020 rover will collect rock and soil samples and send them back to Earth for analysis by the Mars Sample Return mission.
The European Space Agency is also planning to launch a similar mission to Mars in coming years.