Mars may have once held as much as water as our own Arctic Ocean

6 Mar 2015

A NASA illustration showing what Mars' northern ocean could have looked like. Image via NASA/GSFC

Having spent decades attempting to discover evidence of life on our neighbouring planet Mars, NASA researchers now say at one point the planet may have had as much water as our Arctic Ocean.

With the help of NASA’s Very Large Telescope based in Chile and the WM Keck Observatory and NASA Infrared Telescope Facility in Hawaii, scientists analysed the water signatures found in Mars’ atmosphere and found that approximately 4.3bn years ago, the entire surface of the planet could have held water able to reach a depth of 450ft.

However, the team believe it to be more likely that an ocean covered half of the planet’s northern hemisphere with some areas of this vast ocean reaching depths of almost 1.6km.

Interestingly, their vast array of Earth-based telescopes and analysis equipment were able to find traces of two different types of water; the first being the one we’re most familiar with, H2O, and the second being HDO, a naturally occurring variation in which one hydrogen is replaced by a heavier form, called deuterium.

By comparing the findings of water trapped in a 4.5bn-year-old Mars meteorite with those on the planet currently, the researchers were able to show that the volume of water held on the planet’s southern and northern ice caps is 6.5 times less than it was compared with 3.7bn years ago.

This would put the estimated volume of Mars’ early ocean at somewhere in the region of 20m cubic kilometres.

“With Mars losing that much water, the planet was very likely wet for a longer period of time than was previously thought, suggesting it might have been habitable for longer,” said Michael Mumma, a senior scientist at Goddard and the second author on the paper published in Science magazine.

The next steps to determine more detailed analysis of the planet’s wet past will take place next year when a Mars lander mission called InSight will launch to take a first look into the deep interior of the planet.

NASA is also participating in the ESA’s (European Space Agency) 2016 and 2018 ExoMars missions, which will provide telecommunication radios to the ESA’s 2016 orbiter as well as a critical element of the astrobiology instrument on the 2018 ExoMars rover.

Colm Gorey was a senior journalist with Silicon Republic