Mars might have had liquid water on surface 500,000 years ago

24 Jun 2015

Crater water ice on Mars at Vastitas Borealis, seen by the European Space Agency's Mars Express. Image via ESA

According to a new study, around 500,000 years ago, the same time that Homo sapiens began replacing Neanderthal man, our nearest neighbour Mars may have had active sources of free-flowing water on its surface.

To come to these findings, the team of researchers from Utrecht University in the Netherlands analysed one particular crater on the planet’s surface – Istok – which is approximately 1m years old.

Located in the southern hemisphere of the Red Planet, Istok is far from the reach of either of NASA’s Mars rovers – Curiosity and Opportunity — which meant that the team had to recruit NASA’s Mars Reconnaissance Orbiter and its HiRISE camera, which has provided a wealth of information for researchers already.

According to Popular Mechanics, the team’s analysis of its formation and sediment threw up some surprising findings that suggested that the scale of the gullies and amount of sediment indicated considerable flows of meltwater at one point in time.

Publishing their findings in Nature, Tjalling de Haas and his team said they believe that to achieve the results found, the water would have had to have been at least 7in in depth, which would be more than 10 times the amount of water that has been estimated previously.

A Martian ice age

Based off Istok’s age and analysing the sediments, its last major melting period would have been just 500,000 years ago, incredibly recent as far as space-time is concerned.

According to de Haas, the ice and snow that led to this melting was probably due to the periodic ice ages experienced by Mars, much like those we experience on Earth, but experiences more extreme than our own.

It is now just a matter of determining what could have caused snow and ice to build up in the Istok crater.

“Well, there’s a lot of wind on Mars, and it seems possible that wind could have been blowing an accumulation of snow into sheltered areas around the crater,” said de Haas.

Colm Gorey was a senior journalist with Silicon Republic