Signs of recent ‘Marsquakes’ have been found, indicating that liquid water could be present – and raising hopes of life.
A team from Birkbeck, University of London, used images from the Lunar Reconaissance Orbiter’s HiRISE camera to examine boulders along a fault system, Cerberus Fossae, that cuts across a lava surface just a few million years old.
And they found that the way the boulders had fallen and rolled indicated they’d got there through avalanches caused by quakes – not temperature changes, a common cause of Martian rock falls.
“Both the size of the boulders and the frequency of the boulder falls decreased from a central point along the Cerberus Fossae fault system over a distance of approximately 100 kilometres,” says Dr Gerald Roberts.
“This is consistent with the hypothesis that boulders had been mobilised by ground-shaking, and that the severity of the ground-shaking decreased away from the epicentres of marsquakes.”
The distance of the boulders from the epicenter implies a quake with a magnitude of at least 7.
Most excitingly, the fact it’s still possible to see the tracks left in the dust by the falling boulders implies that the quakes were fairly recent. Indeed, says the team, it’s perfectly possible that big quakes are still taking place today.
And that could mean life. The most obvious cause of quakes in the area is the nearby volcano, Elysium Mons. If that’s still active, it could be supplying heat, and melting any water around.
“It is this link between life, volcanism and active faulting that makes the boulder data we have collected so intriguing,” says Roberts.