Mars may have hosted life earlier than Earth did, study says

A new study suggests that life may have existed on Marshundreds of millions of years prior to its emergence onEarth.

The Red Planet may have been ripe for life as early as 4.48 billion years ago, after “life-inhibiting meteorites stopped striking the planet,” according to the study. And it’s possible that life could’ve thrived between 4.2 billion and 3.5 billion years ago, according to comments made by the study’s lead author, Desmond Moser.

“Giant meteorite impacts on Mars between 4.2 and 3.5 billion years ago may have actually accelerated the release of early waters from the interior of the planet setting the stage for life-forming reactions,” Moser said in a statement. “This work may point out good places to get samples returned from Mars.”

Tiny igneous zircon grains within this rock fragment were fractured by the launch from Mars but otherwise unaltered for more than 4.4 billion years. The images was taken with an optical polarizing compound microscope Western’s Zircon & Accessory Phase Laboratory. (Credit: Desmond Moser, Western University)

Tiny igneous zircon grains within this rock fragment were fractured by the launch from Mars but otherwise unaltered for more than 4.4 billion years. The images was taken with an optical polarizing compound microscope Western’s Zircon & Accessory Phase Laboratory. (Credit: Desmond Moser, Western University)

The study analyzed some of the oldest known Martian minerals, looking at zircon and baddeleyite grains seen in Martian meteorites, utilizing electron microscopy and atom probe tomography.

The planet Mars showing Terra Meridiani is seen in an undated NASA image. REUTERS/NASA/Greg Shirah

The planet Mars showing Terra Meridiani is seen in an undated NASA image. REUTERS/NASA/Greg Shirah

“[Ninety-seven percent] of the grains exhibit weak-to-no shock metamorphic features and no thermal overprints from shock-induced melting,” the study’s abstract reads. “By contrast, about 80 [percent] of the studied grains from bombarded crust on Earth and the Moon show such features. The giant impact proposed to have created Mars’ hemispheric dichotomy must, therefore, have taken place more than 4.48 Gyr ago, with no later cataclysmic bombardments.”

Mars is generally assumed to have formed approximately 4.6 billion years ago and Earth soon followed, approximately 60 million years later. Life is generally assumed to have first appeared on Earth approximately 3.5 billion years ago.

The research was published earlier this week in the scientific journal, Nature Geoscience.

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