New Evidence Suggests Mars Has Been Cold and Dry U.S. Geological Survey

U.S. Geological Survey (USGS) scientists studying Mars have discovered minerals with profound implications for the past history of the planet. The mineral olivine, an iron-magnesium silicate that weathers easily by water, has been found in abundance on Mars. The presence of olivine implies that chemical weathering by water is low on the planet and that Mars has been cold and dry throughout its geologic history. New surface maps of Mars, developed by USGS scientists through a monumental set of 500 trillion calculations, provide amazing clarity and allow for more detailed study of the planet’s minerals. “The large expanses of olivine, about one-million square miles, means chemical weathering on Mars is very low and has been low for most of its geologic history. This information contradicts a popular view of a past warm, wet period in Mars’ geologic history,” said USGS scientist Dr. Roger N. Clark at the annual meeting of the American Astronomical Society Division of Planetary Sciences in Pasadena, Calif. “If the warm period never occurred, other explanations for Mars’ large canyons are warranted, and some have been proposed by other researchers.”