There’s a Giant, Salty Lake on Mars – What Does This Mean For Us?

Water is considered essential to life and scientists have long sought to prove that the liquid is present on Mars.

The search for life on Mars just got a lot more interesting.

After years of speculation (and hope), researchers have finally found evidence of an existing body of liquid water on the red planet. This headline-making announcement sent shockwaves among Earthlings, as it raises the possibility that we are not alone on this lonely Blue Planet teeming with life and strife.

According to a study published in the journal ‘Science’, scientists have reported the detection of a salt-laden lake that sits under the southern polar ice-cap of our planetary neighbour. Using radar on an orbiting spacecraft, the reservoir is measured to be about 20 km (12 miles) across and located about a mile (1.5 km) beneath the icy surface.

As we know, water is fundamental to life here on Earth and scientists have long sought to prove its existence on Mars. So whether any planet other than Earth harbours life has been one of the most consequential questions in science. Although the new finding offers hope, it’s a far cry from sampling the water and getting tangible evidence.

Although it may take years to verify whether there is anything living in this body of water that resembles a sub-glacial lake on Earth, there is no reason we shouldn’t take out our copy of ‘The Martian’ and watch it all over again.

How Was it Discovered?

To find the water body on the red planet, radar instruments like MARSIS (Mars Advanced Radar for Subsurface and Ionosphere Sounding) examined the surface and immediate underlying surface by sending out a signal and examining what bounced back, according to Associated Press.

Italian researchers analysed the signals collected over three years by the European Space Agency's Mars Express spacecraft. Their results suggested that a 12-mile-wide (20 kilometre) reservoir sits below the ice about a mile (1.5 kilometres) thick in an area close to the planet's south pole, reported Associated Press.

They spent at least two years examining the data to make sure they'd detected water, not ice or another substance.

Is This a First?

Previous research found possible signs of intermittent liquid water flowing (or at least, having flowed) on the Martian surface. According to a NASA report of 2011, its Opportunity rover had seen a mineral on Mars that could only have formed in the presence of liquid water.

Researchers had found a bright vein of Gypsum, that could only be there if water had, at some point, been present. The finding suggested that billions of years ago warm water flowed through underground fractures in the rocks.

Again in 2015, researchers using data from a NASA satellite orbiting Mars, had said they found clear evidence of intermittent flows of salty water on the red planet. The apparent flows were first noticed in 2010 by Lujendra Ojha, then an undergraduate at the University of Arizona, studying photographs taken by the Mars Reconnaissance Orbiter.

So why is this discovery now such a big deal?

Scientists say the answer lies in the kind of water body that was observed.

“Now we are talking about a potential lake. What we talked about in 2011 and 2015 are probably transient liquid water on the surface — the key word here being “transient”, in that its existence on the surface is temporary. What these guys are talking about is a stable body of lake. If this is indeed the case, then the findings are huge and could have important implications for our search for habitable environments on Mars,” Lujendra Ojha told Tech2.

Does This Indicate Life On Mars?

Finding this new lake buried beneath the Martian surface is another step towards finding an answer to the question “Do real-life Martians exist?”

The answer to the question is – we still don’t know. But it seems that at least we are on the right track.

The discovery of this lake adds to the proof that Mars was once active, at least geologically and chemically, but the question to answer now is whether those processes were enough to produce life. This study made it clear that Mars may have been liveable once.

Professor Mayank Vahia from the Department of Astronomy and Astrophysics at TIFR, Mumbai told Tech2

So even after the confirmation of life forms in the future, there lies the possibility that they may end up to be very primitive life forms such as microbes.

That’s All Well And Good, But What Next?

Now that we know there is a possibility of another type of habitat in which life could be living on Mars in the present day, the next step would be to turn that “possibility” into a confirmation. The next step would be to find out what’s beneath that underground lake.

But that is easier said that done.

The main challenge is to land on Mars as most of the missions till date have landed within about 30° latitude of Mars’ equator, except for Viking 2 and Phoenix landers, both of which landed in Mars’ northern lowlands, according to Newsweek... but the reservoir has been detected in Mars’ southern hemisphere.

But landing on the southern hemisphere is comparatively harder. The north houses the lowlands and has a thicker atmosphere, while the south has less atmosphere to slow the descent and a rougher surface making the landing difficult.

But, while tricky, it is not impossible. And now we have a huge motivation to try harder.

(With inputs from NASA, Tech2, Associated Press and Newsweek.)