Mars may have a lake of liquid water

ESA
/ Wikimedia Commons

• Scientists from the National Institute for Astrophysics
  in Bologna may have found a lake of liquid water on
  Mars.
• Satellite data suggests the water might lie underneath
  the surface of a polar ice cap.
• The researchers used radar to probe the ice cap, and
  their new study suggests the potential lake could be 20
  kilometers long.

We’ve heard it before — there may be a major source of water on Mars, in
ice sheets that lie just under the red planet’s. But
according to a new study published in the journal
Science, liquid water may exist there, too.

Researchers from the National Institute for Astrophysics in
Bologna in Italy used a radar tool on the European Space Agency’s
Mars Express satellite to probe the planet’s ice caps. They
believe three years’ worth of data indicates there could be a
lake of liquid water under the caps that stretches 20 kilometers
across.

The team, led by Roberto Orosei, said this may be the first time
scientists have found liquid water that can remain in a liquid
state for a prolonged period of time, rather than freezing.
Elsewhere on the red planet, it is too cold for water to remain a
liquid — Mars’ average temperature is -81 degrees
Fahrenheit (-62 degrees Celsius).

“If these researchers are right, this is the first time
we’ve found evidence of a large water body on Mars,” Cassie
Stuurman, a geophysicist at the University of Texas who found
signs of an enormous Martian ice deposit in 2016,
told the AP.

Searching for Martian water

In their paper, the researchers suggested that the lake could lie
about 1.5 kilometers below the ice cap’s surface. But they are
not yet certain whether there is really a lake there or how deep
it could be. Until a human expedition or more sophisticated
Rovers can investigate the polar region further, we won’t know
for sure. But for now, liquid water seems to be the most likely
explanation for what researchers observed.

“I really have no other explanation,” Orosei
told the AP.

Radar detection has proved unreliable for gathering information
about Mars in the past. But after reprogramming the radar tool on
the Mars Express satellite — called the Mars Advanced Radar for
Subsurface and Ionosphere Sounding, or MARSIS — radar pulses were
able to penetrate the surface of the ice caps.

The tool measured how radio waves traveled and behaved when
traveling through Mars’ ice caps, then the satellite beamed that
information to Earth. This gave the team an idea of the
composition under the ice caps.

Time was also not on the researchers’ side, however. They had to
wait for the satellite to be in the right place to observe the
caps at night time, a position that has only occurred 30 times in
three years.

Liquid water would have major implications for life on Mars and
future human settlements

Orosei told New
Scientist that a combination of calcium, magnesium,
and sodium salts on Mars can lower water’s freezing point, which
might explain the possibility of a liquid lake.

If it exists, there’s also hope that the water could potentially
host life.

“It is not a place where life would be expected to have an easy
time, but it is possible based upon terrestrial analogues,”
Orosei told New Scientist. The analogues he’s referring to
are places on Earth that researchers
have used to mimic Mars environments to test conditions in
which microbes could survive.

Finding a source of liquid water on Mars would also be exciting
for the prospect that the red planet could one day host a human
settlement. Both Elon Musk and NASA have
released plans to send humans to Mars, maybe as soon as the 2030s.

But there are
huge barriers to any colonization efforts, such as
growing enough food and recycling waste. Pre-delivered
supplies and habitats could sustain human life on the barren
surface for a year or two, some experts say, but long term colonization is a
different matter. Researchers have even highlighted concerns
about how reproduction would work on
Mars, should a self-sustaining settlement ever arise
there, since life in space has
dramatic effects on people’s health.

Despite all these challenges, it’s exciting that there could be
an underground reservoir of water on Mars. Perhaps it could be
tapped as a resource, or maybe it harbors undiscovered clues
about alien life. 

Plus, as Orosei
said in a statement, this discovery may be a clue
that Mars has other hidden bodies of water that are
still waiting to be found. 

“This is just one small study area; it is an exciting
prospect to think there could be more of these underground
pockets of water elsewhere, yet to be discovered,” he
said.