Mystery White Substance, But No Water Yet at Martian Pole

The Phoenix Lander, our favorite robot chemistry lab on Mars, has successfully cooked up some soil in its oven to see if water evaporates from it when heated. So far, no dice. Though the Martian rovers Opportunity and Spirit have found evidence of evaporated water at the equator of the planet, Phoenix hasn't yet… » 6/17/08 2:26pm 6/17/08 2:26pm