SSS 2009-04-17

（单词翻译）

This is Scientific American's 60-Second Science. I'm Adam Hinterthuer. Got a minute?

At Antarctica’s Blood Falls, the ice is stained red by ancient, iron-rich water pouring out of subglacial lakes formed millions of years ago. The cascading¹ water is extremely saline, has almost no oxygen and no real nutrients² to speak of. But that hasn’t stopped life from finding a niche³. According to a report in the April 17th issue of Science, a population of microbes has called the frigid⁴ place home for millennia⁵.

Even though carbon-based nutrients are missing, these microbes thrive in pockets of water trapped under the glacier⁶ by making do with what they have—which is lots of sulfates and iron. The microbes use iron molecules⁷ that the glacier scours⁸ from the bedrock to react with available sulfate, which lets the microbes then metabolize it into a useable form.

The report suggests this is one way life could have survived past eras when Earth was covered in ice. It also shows that life will spring up in the most unlikely places using some very clever chemistry. So when we’re looking for life on Mars, focus less on little green men and more on little red microbes.

Thanks for the minute for Scientific American's 60-Second Science. I'm Adam Hinterthuer.