This morning one of our Year 6 students asked me if I thought there might be life on another planet. His class had been talking about it, using this web site for a reference. I had recently heard this podcast from The Naked Scientists (Cambridge University) about life on Mars.
In one portion of the podcast, Chris Smith says
"Writing in this week's Science, Cornell researcher Steven Squyers and his colleagues describe how the movement of their rover, Spirit, which has a broken wheel, carved a furrow into the Martian surface, revealing a layer of very white-coloured material. Intrigued, the team turned the rover's instruments on the light coloured layer and identified it as silicate, a mineral which forms around structures such as hydrothermal vents and fumaroles when hot mineral-laden water emerges, cools and drops its cargo of salts.
"On Earth, environments like this contain abundant forms of life, and silica turns out to be extremely good at preserving them. So this discovery, say the researchers, is important for two key reasons. First it confirms that Mars had significant water in the past, but second it also pinpoints an important place to look for life in future."
Later in the show, he interviews Susan Conway, of the Open University, about what shaped the surface of Mars. Here's a bit of their conversation from the end of the interview:
(Chris has asked Susan her opinion about what formed the gullies visible on Mars in recent photographs. She explains that there are several hypotheses.)
Chris - What's your gut feeling at the moment?You can subscribe to the Naked Scientist podcast through iTunes, or on the program's web site.
Susan - I think it's water, personally. It's all up for debate, we'll have to see
Chris - If it is water, looking at the terrain, when do you think water last ran?
Susan - It could be anything in the last 100,000 years.
Chris - Which is very recent, isn't it?
Susan - it is very recent, yes.
Chris - Which means, if there was life there it could still have been viable up until 100,000 years ago which is a blink of an eye isn't it?
Susan - Yeah. If the water formed these features and then has gone back into the ground and we still have liquid water beneath the ground little micros still could be living there in the rock, eating the rock, eating the water and still sitting there waiting for us to discover them."
You can download the Life on Mars episode below:
If you want to read more about the concept of life, go to this Wikipedia for Schools page. There is an interesting article about extra-terrestrial life at this page of the Wikipedia for Schools,