The Enigma of the Martian Soil

摘要

Since the two Viking landers touched down on Mars in 1976, the ubiquitous surface soil and dust have defied attempts to model their properties and understand how they formed. The fine soil that gives Mars its red color holds clues to the presence of liquid water, the rock weathering processes, and the potential biological history of the planet. Through dust storms, it plays a key role in the climatic cycles of Mars. It may hamper exploration by interfering with robotic and human performance, but mayalso offer a valuable resource by supplying water and fuel and supporting plant growth and food production. What is known and what is still puzzling about the martian soil? And do we have similar soils on Earth? Recent results from the Mars exploration rovers Spirit and Opportunity and from terrestrial studies add to our understanding and open new questions.