Not to be outdone by NASA’s Opportunity and Curiosity rovers, the Spirit rover provided meteorites and rocks on Mars’ surface that indicate that surface was oxidized long ago. In fact, it appears Mars had an oxygen-rich atmosphere at least 1.5 billion years before Earth, if the data collected is correct.
Researchers from Oxford University recently published work in the journal, Nature, that supports their theory that oxygen may have existed in the planet’s atmosphere around 4 billion years ago. They came to this conclusion by comparing different Martian rocks, those obtained from meteors and those studied by the various rover missions.
Through comparing their chemical compositions, the scientists discovered that in the different samples of volcanic rock they had, the meteoritic samples were completely different, showed five times more nickel than those rocks studied in the Gusev crater by the NASA rover, Spirit. The researchers proposed the volcanic rock found on the planet now, about 3.7 billion years old, showed greater evidence of oxidation than the meteoritic samples a mere 1.4 billion years old.
Talking about the research, Dr. Bernard Wood, professor of Oxford University’s Department of Earth Science, said, What we have shown is that bot meteorites and surface volcanic rocks are consistent with similar origins in the deep interior of Mars, but that the surface rocks come from a more oxygen-rich environment, probably caused by recycling of oxygen-rich materials into the interior.
Dr. Wood went on to explain that the oxygen in the atmosphere would have most likely come from the breakdown of water into its component parts – hydrogen and oxygen – most likely from the interaction of water vapor in the atmosphere being radiated by the sun. He said that this oxidation was what gave Mars its distinctive red color. He added the planet was most likely warm, wet and rusty and possessed the oxygen billions of years before Earth itself augmented the life giving gas.
NASA’s Spirit rover was sent to Mars in 2004 and spent six years traveling the Martian surface. It ceased to be useful in 2010 and was removed from NASA’s Mars rover mission in mid-2011
The most tantalizing mystery remaining is how oxygen may have occurred on Mars. On Earth, early microbial life consumed carbon dioxide, which was rich in the early atmosphere, and produced oxygen. Eventually, enough oxygen built up enough for animal life to become possible.
Not so in Mars, although it is possible that chemical reactions made the early Martian atmosphere rich in oxygen. On the other hand, it is also possible that primitive life could have made it, too.
While it still seems more logical to assume that chemical processes were responsible for the oxygen on Mars, it will take more scientific study before we will ever know the truth. At this point, several past studies have hinted at the possibility of life, but none have ever been conclusive. In fact, the majority of studies suggest Mars has always been sterile.