"Radar Evidence of Subglacial Liquid Water on Mars" in Science, 3 August 2018.

R. Orosel, et al. "Radar Evidence of Subglacial Liquid Water on Mars" in Science, 3 August 2018, vol361 issue 6401 in the issue of pp 429-522. Original wrappers. Very Fine copy. "Mars is known to host large quantities of water in solid or gaseous form, and surface rocks show clear evidence that there was liquid water on the planet in the distant past. Whether any liquid water remains on Mars today has long been debated. Orosei et al. used radar measurements from the Mars Express spacecraft to search for liquid water in Mars' southern ice cap (see the Perspective by Diez). They detected a 20-km-wide lake of liquid water underneath solid ice in the Planum Australe region. The water is probably kept from freezing by dissolved salts and the pressure of the ice above. The presence of liquid water on Mars has implications for astrobiology and future human exploration."--Abstract. 585 citations.