Free Astronomy Magazine September-October 2018

4 Mars, the God of War, is losing the fight to hide its mystery. Leading the charge are orbiters and landers that have revealed an ancient ocean and a thick atmos- phere, both lost over the planet’s history. The story of the Martian surface is far from over − a recent study reports the possible discovery of a subglacial liquid water lake, revealing that a diversity of local environ- ments may still exist close to the Martian surface. by Damian G. Allis, Ph.D. NASA Solar System Ambassador damian@somewhereville.com A possible subglacial lake on Mars SEPTEMBER-OCTOBER 2018 PLANETOLOGY O n the back- ground, a simu- lated 3-D perspective view of a Martian polar cap, created from image data taken by the THEMIS instrument on NASA's Mars Odyssey spacecraft. [NASA/JPL/Arizona State Univ., R. Luk]