A new study shows that the atmospheres of planets Earth and Mars separated in significant ways in the early days of the 4.6 billion year evolution of the solar system. The study, Isotopic links between atmospheric chemistry and the deep sulphur cycle on Mars, has been published by the Nature Journal on April 17.
Lead study author Heather Franz, formerly a research associate at the University of Maryland, and co-author James Farquhar, geology professor at UMD. At present, Franz works at the Goddard Space Flight Center of NASA with the science team of Curiosity rover.
The study discloses that the geologists, who examined the 40 meteorites that came from Mars and dropped in to the Earth, unraveled the secrets of the atmosphere in Mars concealed in the ancient rocks' chemical signatures. The 40 meteorites symbolize over half of the distinctive known meteorites in Mars. The study researchers measured the sulfur composition of the 40 meteorites of Mars, a bigger number than their previous analyses.
"Our data provide strong evidence that assimilation of sulphur into Martian magmas was a common occurrence throughout much of the planet's history," the study notes.
Based on the report released by the University of Maryland, the results of the discovery will serve as a guide for researchers in understanding if life has ever existed or exists on the Red Planet as well as how water flowed there in the past. Water is now absent from the surface of Mars, the report further said.
The UMD report also said out of over 60,000 discovered meteorites on Earth, merely 69 have been believed are pieces of rocks exploded off the surface of Mars. These meteorites have been considered as "igneous rocks" formed on Mars, emitted into space after the slamming of a comet or asteroid into the red planet, and then made land on Earth.
Of the meteorites in the study, the oldest is around 4.1 billion years old, whose formation dates back during solar system's infancy stage. The youngest meteorites, meanwhile, are aged between 200 million and 500 million years.
The study of Martian meteorites of varied ages is significant to scientists because it helps them examine Martian atmosphere's chemical composition all throughout history. It also helps them learn and understand if Mars has been welcoming of life, because while Earth and Mars have the same basic elements for life, Mars has much-less favorable conditions such as cold temperatures, arid surface, ultraviolet radiation coming from the Sun and radioactive cosmic rays. Though there was a sign of past milder conditions because several geographical features of Mars were evidences of water formation.
The UMD report also said though the scientists aren't sure under what conditions helped the liquid water to exist on Mars' surface, what likely played a role is volcanoes' release of greenhouse gases such as Sulfur. Mars has plenty of Sulfur, which may have been one of the gases warming its surface and providing microbes' source of food.
Meteorites contain a wealth of information on Martian Sulfur, so the study researchers made an analysis of the sulfur atoms found in the rocks. Some Sulfur in these Martian meteorites came from magma or molten rock, which landed on the surface during volcanic eruptions.
After much analysis using state-of-the-art methodology, the researchers discovered that the chemical reactions that involved Sulfur in the atmosphere of Mars were diverse than those previously found in the geographical history of the Earth-which was the basis of the scientists that the early atmospheres of these two planets were very varied. The precise nature of their differences remains unclear, though.
Other evidences, however, suggest that much of the atmosphere of Mars got lost following the formation of the solar system. This is also the reason why Martian atmosphere was thinner than the Earth's atmosphere and with poorer concentrations of gases including carbon dioxide. Franz said which is also why Mars today is very cold for liquid water, though the case may not have always been this way.
