Thanks to NASA’s Mars Curiosity rover, we’re learning new things about the red planet nearly every day. However, we’re also learning a few new details about ancient Mars here on Earth, thanks to a meteorite from the planet discovered over 30 years ago.
The meteorite fell on Antarctica around 13,000 years ago, and has since been analysed to discover whether life once flourished on the now barren landscape of the red planet. Now, a new study of the oldest meteorite from Mars has added evidence to the theory that the red planet likely held smaller seas that allowed life to flourish.
Scientists from the University of California, San Diego, NASA and the Smithsonian Institution recently studied the minerals trapped within the rock and released a report giving us more insight into what Mars was like in its early years.
“Minerals within the meteorite hold a snapshot of the planet’s ancient chemistry, of interactions between water and atmosphere,” says Robina Shaheen, a project scientist at UC San Diego.
The meteorite itself isn’t much to look at, but it fell to Earth over 10,000 years ago. Called ALH84001, scientists believe that its rock is actually solid magma from a Martian volcano that erupted over four billion years ago. Most importantly, liquid, potentially in the form of water, flowed into the rock at some point and deposited minerals within it, including carbonates.
Carbonates are made up of carbon and oxygen, and the source of both of these elements determines what isotopes are present. Scientists can then analyze the chemical signature these isotopes left behind to reveal how much water and ozone was present on Mars when they formed.
“When ozone reacts with carbon dioxide in the atmosphere, it transfers its isotopic weirdness to the new molecule,” Shaheen explained. And the more water, the smaller the weird ozone signal.
The research measured a pronounced ozone signal in the carbonates within the meteorite, suggesting that water once existed on Mars. Though, that’s not to say that our nearest neighbor harbored vast oceans like those on Earth. It was more likely that the early Martian landscape held smaller seas.
“What’s also new is our simultaneous measurements of carbon isotopes on the same samples. The mix of carbon isotopes suggest that the different minerals within the meteorite had separate origins,” Shaheen stated. “They tell us the story of the chemical and isotopic compositions of the atmospheric carbon dioxide.”
But what about life? Did the meteorite uncover any secrets about previous life on Mars? Although carbonates sometimes suggest microbial life, that isn’t the case here.
Of course, this new information also raises new questions. When did Mars, and Earth, get water? And where did Mars’ water go?
Abstract Source: https://goo.gl/3sMLnF.