It’s an exciting time for the possibility of life on Mars. A recent study has found that Mars had the potential to support life much earlier than scientists once believed. The finding means that Mars could have potentially hosted life even before life on Earth arose.
The study, conducted by an international team of researchers led by Western University and published in the journal Nature Geoscience, found that huge, life-destroying meteorites stopped striking the Red Planet about 4.48 billion years ago. Scientists previously believed that the bombardment didn’t end until 3.8 billion years ago.
Much of the scientific community agrees that Mars had liquid water on its surface before 3.8 billion years ago due to a denser atmosphere leading to higher temperatures. Furthermore, the impacts could have freed trapped water in Mars’ interior. These discoveries bode well for life forming on the Red Planet, possibly 500 million years before Earth.
The researchers made the discovery by analyzing ancient meteorites they believe originated on Mars’ southern highlands. When they looked at the Red Planet rocks on an atomic level, they found that the minerals remained unchanged since they formed near the surface of Mars.
The scientists then compared the Martian rocks to Earth and Moon rocks. They found that 80 percent of the Earth and Moon rocks experienced change under monumental temperature and pressure. This fact means the Mars rocks didn’t experience the bombardment that the Earth and Moon rocks did.
Mars may have dodged the bullets, so to speak.
The atomic level analysis took place at Western University’s Zircon & Accessory Phase Laboratory, the only one of its kind in the United States. Western Earth Sciences and Geography Professor Desmond Moser led the team. “This work may point out good places to get samples returned from Mars,” Moser said.
NASA is sending another rover to Mars in 2020. The rover, which will touch down in early 2021, will collect samples for future missions to return to Earth. Moser and his team’s work has been crucial in deciding where to collect these samples. But another discovery on Mars by the Curiosity rover has also revved up excitement at the possibility of finding signs of life on Mars.
Other Signs of Life
Recently, Curiosity detected the highest levels of methane ever recorded on Mars. Methane can arise from geologic processes but is also a byproduct of living organisms. The rover, however, can’t detect whether the methane comes from geological or biological sources.
While follow-up experiments have found that the methane levels have decreased, NASA scientists believe that it came from one of the “transient methane plumes” they have seen in the past. Curiously, the plumes seem to ebb and flow with the seasons. Although the methane levels aren’t as high as NASA once believed, they still present something of great interest in the search for signs of life on Mars.