Scientists have recently conducted a thorough analysis on around 40 Martian meteorites that crashed into the Earth. Their findings indicate key differences between the Earth's atmosphere and the early Martian atmosphere.
The geological analysis hints at some point in the early history of the Solar System, the early atmospheres of the Earth and Mars diverged in several very important ways. This divergence can have important implications to a number of key questions that scientists have been trying to answer. First of all, these differences can help answer the question of whether life ever existed on the Red Planet. Secondly, the new findings may also shed light on the practicality of terraforming Mars into a planet suitable for human habitation sometime in the future.
The University of Maryland researchers were led by Heather Franz, a scientists from the NASA Goddard Space Flight Center's Curiosity Rover team. Franz was also a former research associate from the University of Maryland. The team published its findings in the online journal Nature.
The team analyzed the sulfur content of the Martian meteorites. While previous studies have also used similar methodologies to analyze the composition of Martian space rocks, this is the first time that a sample size of 40 meteorites has been used. Scientists who worked on similar studies in the past only analyzed a handful of meteorites.
The meteorites analyzed in the new study were determined to be igneous rocks that may have been blasted into space when a large comet or asteroid slammed into the Martian surface at some point in the past. Some of these meteorites are very old with the oldest sample being around 4.1 billion years old. Considering that the Solar System is around 4.6 billion years old, these ancient rocks may hold valuable information about the early state of Mars.
The team found that early conditions on Mars were much less favorable to supporting life compared to the conditions on Earth billions of years ago. The team also confirmed that sulfur was a very abundant element in Mars. However, further analysis showed that the sulfur on Mars was the product of photochemical processes that occurred in the early atmosphere of Mars. These reactions were markedly different from chemical reactions that occurred on Earth.
"Climate models show that a moderate abundance of sulfur dioxide in the atmosphere after volcanic episodes, which have occurred throughout Mars' history, could have produced a warming effect which may have allowed liquid water to exist at the surface for extended periods," said Franz. "Our measurements of sulfur in Martian meteorites narrow the range of possible atmospheric compositions, since the pattern of isotopes that we observe points to a distinctive type of photochemical activity on Mars, different from that on early Earth."
The team's findings regarding the early atmosphere of Mars may also be very important for future plans to terraform the planet. Many scientists are also calling into question the practicality of terraforming Mars. Some experts say that it would be far easier to fix the current problems on Earth compared to changing an entire planet to suit human habitation.
