A huge lake of liquid water under the south pole of Mars

This new discovery comes from research using the Mars Express spacecraft that orbits around the red planet since December 25, 2003.

MARSIS (Mars Advanced Radar for Subsurface and Mars) is one of the instruments worn by Mars Express. Ionosphere Sounding), which allows researchers to use radar to study the characteristics beneath the surface of the planet.

With the help of observations over a period of four years, a team of Italian researchers found a large saltwater lake 1.5 kilometers south of Mars Polar Cap. This lake is at least 20 kilometers long and seems to be a permanent feature

More than droplets

The reason people are excited about this discovery is because on Earth, you find liquid water, you find life. NASA has long espoused a philosophy of "tracking water" in its astrobiological research program – trying to answer the question "Are we alone?"

Over the last two decades we have seen mission after mission to Mars. Some, like Mars Express, are orbits, while others (like the incredible Spirit and Opportunity) are rovers. A unifying theme throughout these missions was their attempts to see if Mars once had the right conditions for life to exist and prosper.

Thanks to them, we found plenty of evidence that Mars was once hot and humid. We also have evidence that liquid water can still be found on the surface of Mars from time to time.

But until today, the evidence of modern water all pointed to fleeting moments – droplets condensing on the Mars Phoenix liner; or evidence of brief saltwater outflows in the Martian valleys

Compared to today 's discovery, these earlier discoveries are a drop in the ocean.

Mars Has a Lake

The latest observations reveal something remarkable: a salt lake buried deep under the ice, which seems to be a permanent feature rather than a transient phenomenon.

The comparison that comes to mind is the myriad of lakes buried under the ice of Antarctica. Until now, more than 400 of these lakes have been found beneath the surface of the frozen continent.

Perhaps the most famous is Lake Vostok – one of the largest lakes in the world, buried and hidden. But the one I want to call attention to is Lake Whillans.

Whillans Lake is buried some 800 meters under ice in West Antarctica. In 2013, a team of researchers managed to drill in the lake and collect samples. What did they find? That he was teeming with microbial life. In other words, the best terrestrial analogues for the newly discovered Martian lake are not only habitable, they are inhabited . Where there is water, there is life.

Is there life on Mars?

Finding this new lake, buried under the south pole of Mars, is another exciting step in our journey to discover the red planet. Can there be life there under the ice?

The short answer is that we still do not know. But it seems like the perfect place to look. What we know is:

• Mars was once hot and humid, potentially with oceans, lakes and rivers
• On Earth, where you find water, you find life
• hot and humid march to cold and arid Mars that we see today occurred millions of years
• Life adapts to changing environments, as long as this change It's not too fast or dramatic.

So what do you get if you put it all together? Well, it is there that things become speculative.

But let's imagine that in the distant past, Mars had life. Perhaps life was born here, or maybe it was delivered from the Earth, hitching a meteorite.

Once life is established, it is incredibly difficult to get rid of it. For millions of years, Mars has been cooling down and its water is locked up in permafrost. Its atmosphere has thinned and it has become the red planet we see today.

But perhaps, perhaps, that life could have followed the water – move underground, where she could have found a niche, in a dark and salty lake, buried under the ice of the polar cap south of Mars.

All is well, but after?

This is a question of speculation, but it shows the kind of thought processes that have led our exploration during March for the past two decades.

Now that we know for sure that there is a reservoir of liquid water just beneath the surface of the planet, astronomers around the world will think of ways to get down to that water to see what who finds it.

what does. Landing on Mars is a challenge in the best case, and the vast majority of missions so far have landed at about 30 ° latitude from the equator of Mars. The two exceptions are the Viking 2 and Phoenix landers, both of which landed in the northern lowlands of Mars.

In addition, the landing on the southern hemisphere of Mars is even more difficult. The north is the plain and the atmosphere there is noticeably thicker, and the surface smoother (as befits, potentially, the floor of an old ocean).

To the south, you have less atmosphere to slow your descent and a rougher surface to make your landing harder.

But even if it is difficult, it is not impossible. And now we have a huge motivation to try.

It would not surprise me if, in a decade, we see missions designed to visit the south pole of Mars and descend to this great lake, to see what is hiding inside.

Learn more:
Liquid water is buried under the Martian landscape, according to a study