A team of scientists have detected a lake of liquid water underneath Mars' southern polar ice cap, a discovery that is being considered as a "game changer" in the search for alien life.

The liquid water on Mars, which may be part of a larger network of lakes, adds to speculation that life may have existed on the Red Planet or perhaps that life is still there, hidden beneath the surface.

Is There Water On Mars?

Italian researchers from the Italian Space Agency published a new study on the Science journal detailing their discovery of a lake of liquid water under the southern polar ice cap of Mars.

The researchers gathered the evidence using MARSIS, or the Mars Advanced Radar for Subsurface and Ionosphere Sounding instrument, which is on the Mars Express spacecraft of the European Space Agency.

From May 2012 to December 2015, MARSIS surveyed the southern ice cap of Mars by sending radar pulses through the surface and measuring how the radio waves were reflected back to the Mars Express. The survey returned 29 sets of radar samples that showed drastic changes in the signal from about a mile below the Red Planet's surface.

The anomaly stretched around 12.5 miles across and resembled the lakes underneath the Greenland and Antarctic ice sheets. The radar also showed the feature's brightness, which signaled that there was liquid water.

When MARSIS principal investigator and Italian National Institute for Astrophysics planetary scientist Roberto Orosei and his colleagues made the discovery, they decided to keep quiet. The team first wanted to make sure that they indeed found liquid water in Mars by trying to come up with other possible explanations for their discovery.

"After years, literally a couple of years of ... discussion, debate and let's say general head-scratching," said Orosei, "we really felt confident that any other explanation would fail."

Is There Life On Mars?

Ellen Stofan, the John and Adrienne Mars Director at the Smithsonian's National Air and Space Museum, said that finding liquid water on Mars is a very exciting discovery due to the fact that life on Earth evolved from liquid water. This meant that the search for alien life was always hand-in-hand with the search for liquid water in other planets.

Open University's Dr. Manish Patel, however, said that the discovery of liquid water does not make scientists move closer to finding life on Mars. The possibility that there is an underground network of lakes with liquid water on Mars, meanwhile, will require further studies.