Newly discovered ‘zircon’ may hold the secret to life on Mars

Are we alone in the Universe? Billions of dollars are being spent trying to answer that simple question. The implications of finding evidence for life beyond Earth are staggering. The “before and after” mark would punctuate human history.

Mars is currently the most popular exploration target to search for evidence of life elsewhere. Yet little is known about its early history. Our research on a Martian meteorite provides new clues about early surface conditions on the red planet.

Windows into the past

Today Mars is cold and inhospitable. But it may have been more Earth-like and habitable in a bygone era. Landforms on Mars record the action of liquid surface water, perhaps as early as 3.9 billion years ago.

Like Earth, early Mars was subject to a global bombardment from chunks of rock and ice floating around the Solar System. Giant impacts both destroy and create favorable environments for life. So to untangle when conditions suitable for life may have arisen on Mars, we have to track the history of both water and impacts.

A flotilla of rovers and orbiting spacecraft have been dispatched to Mars, with two NASA rovers specifically exploring impact craters for evidence of past life. Samples collected by rovers will be returned in future missions.

For now, meteorites are the only samples of Mars available to study here on Earth. Martian meteorites are born when an impact on Mars ejects rocky fragments that later intercept Earth’s orbit. Most Martian meteorites are igneous rocks, such as basalt. One meteorite, NWA 7034, is different, as it represents a rare sample of the surface of Mars.