Underground Network Of Hidden Lakes Discovered On Mars
ESA's Mars Express spacecraft has discovered several lakes of liquid water buried under the ice in the south polar region of Mars. The spacecraft's radar instrument, MARSIS (Mars Advanced Radar for Subsurface and Ionosphere Sounding), revealed one subterranean reservoir buried about 1.5 km below the ice in 2018. Now three more new lakes have been discovered. The largest underground lake is about 20 x 30 km and is surrounded by several smaller lakes. The water is thought to be very salty so that it remains liquid at low temperatures.
“The existence of a single sub-glacial lake can be attributed to ad hoc conditions, such as the presence of a volcano under the ice sheet, or some other situation unique to the specific location where we found the first sub-glacial lake,” explains geophysicist Elena. Pettinelli from Roma Tre University. She led the investigation together with colleague Sebastian Emanuel Lauro.
"The discovery of an entire system of lakes suggests that their formation process is relatively simple and possibly common."
Mars was once warmer and wetter with water flowing over its surface, just like early Earth. While it is not possible for water to remain liquid on the surface today, the new result opens the possibility that there is an entire system of ancient lakes underground, perhaps millions or even billions of years old. They would be ideal locations to look for evidence of life on Mars, although they are very difficult to reach.
Sub glacial lakes are also known on Earth, such as Lake Vostok in Antarctica. They can harbor unique ecosystems and provide useful analogies for astrobiologists investigating how life can survive in extreme environments. The techniques used to analyze the radar data on Mars are similar to those used in the survey of subglacial lakes in Antarctica, Canada and Greenland.