Hints: William Boynton the University of Arizona Mars Earth Martian ice concentration degrees centigrade

William Boynton is professor of planetary sciences at the University of Arizona. And he's dedicated his life to looking for water on Mars. The link between life and water is very strong. Even here in the desert, there's life all around us. Now when looking for life on Mars, we use our basis of knowledge on Earth. And on Earth we know life requires water. So on Mars, we're gonna be looking for the places where we can find water. Just like the desert, Mars may look dry but there are signs of water there. It's been known for almost a century that there are icecaps at the Martian poles. When we look up at Mars, we see a dry, dusty planet. It doesn't look like a place for life. But there's tiny amounts of water in the atmosphere. And we know there are ice concentrations in the poles. So we're actually very optimistic that because there is at least, a speck of water on Mars, there might be a speck of life. However, while the poles contain water ice, temperatures there can reach a staggering minus 150 degrees centigrade which meant these were not good places to search for life.

这篇材料你能听出多少？点击这里做听写，提高外语水平>>