Halos on Mars Could Mean a Longer Life-Friendly Past [electronic resource].
Published
Washington, D.C. : United States. Dept. of Energy, 2017. Oak Ridge, Tenn. : Distributed by the Office of Scientific and Technical Information, U.S. Dept. of Energy
Lighter-toned bedrock that surrounds fractures and comprises high concentrations of silica—called “halos”—has been found in Gale crater on Mars, indicating that the planet had liquid water much longer than previously believed.