Antarctica is covered by very thick ice. But under the ice, there are hundreds of lakes of liquid water. The biggest one is Lake Vostok. It lies under about 4 kilometers of ice.

Why doesn't the water freeze? Heat comes up from inside the Earth, and the thick ice keeps the heat in like a blanket. Scientists even found tiny living things in another lake under the ice.

Under the ice of Antarctica, there are hundreds of lakes of liquid water. A list made in 2022 counted 675 of them. The largest, Lake Vostok, lies about 4 kilometers below a Russian research station. The lowest temperature ever recorded on Earth's surface, minus 89.2 degrees Celsius, was measured at that station.

Scientists found the lakes by sending radar signals down through the ice from airplanes. Water reflects these signals strongly, so the lakes show up clearly.

Why don't they freeze? Heat comes up from inside the Earth, and the thick ice works like a blanket. The great weight of the ice also lowers the melting point. In 2013, an American team drilled into a different lake and found many kinds of microbes living without sunlight.

Beneath the Antarctic ice sheet lies a hidden network of lakes, with 675 counted in a 2022 inventory. The largest, Lake Vostok, sits under roughly 4 kilometers of ice and stretches for over 200 kilometers. Although airborne radar hinted at water in the 1970s, a 1996 study combining radar and seismic data revealed the lake's enormous size. These lakes remain liquid because geothermal heat rises from below, the thick ice insulates it, and the immense pressure lowers the melting point of ice.

Whether life exists in Lake Vostok is still disputed: microbial DNA was reported from lake water that had refrozen onto the ice, but contamination from drilling fluid could not be ruled out. Clearer evidence came from Subglacial Lake Whillans, where an American team used a clean hot-water drill in 2013 and found diverse microbes that apparently obtain energy from rocks and minerals. Satellites also show that many lakes are connected and periodically fill and drain. However, Whillans is shallow and active, unlike deep, isolated Vostok, so findings from one should not simply be applied to the other.