30 June 2000
Vol 288, Issue 5475

About The Cover

Cover image expansion

COVER This high-resolution image of the surface of Mars shows a 3-km-wide area of an impact crater's south-facing wall (54.8°S, 342.5°W). The gullies seen here may have formed by groundwater seepage and surface runoff, and the location and youth of these gullies suggest that liquid water may exist in the shallow martian subsurface today. This image was acquired in September 1999 by the Mars Global Surveyor Mars Orbiter Camera. See page 2330 [Image: Malin Space Science Systems/Jet Propulsion Laboratory/NASA]