Martian Winter, Battery Life Add Urgency to Rover Mission

摘要

Now that NASA's Opportunity rover has established that there is a locale on Mars where rocks were once drenched in water, it is in a race against time and battery life to learn how widespread and deep the water was. Was there a giant sea, or did less conspicuous groundwater percolate locally through the subsurface of Meridiani Planum? Opportunity has yet to creep out of the shallow depression in which it fortuitously landed. Additional observations, potentially crucial, will be made in the next week or so at its home base. Then the robot will hit the road, with plans for two lengthy journeys in search of additional rock outcroppings. What is known so far is that a curb-high shelf of bedrock at the landing site has been chemically altered in the presence of enough water to soak the outcropping, NASA scientists said March 2. The rock is infused with "enormous amounts" of salt, which on Earth occur when salts precipitate out of water over time, and especially when the water evaporates.