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Q & A: Searching for Extraterrestrials

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Most recent answer: 10/22/2007
How do we search for extraterrestrials?
- Jeff (age 15)
There are some people who spend a lot of time looking for extraterrestrials, and some of them are quite serious about it. Have a look at 's web page. A search is underway analyzing radio telescope data for patterns that may indicate some kind of intelligent life out there is sending us signals. The universe (and even our galaxy) is really really big, so you have to look in lots of places for signals that could be very weak and buried in all kinds of naturally-occurring background noise. The SETI project even enlists people with internet-connected computers to help analyze their data for them.

One of the goals of NASA's is to search for signs that life could have existed at one point on the surface of Mars. We haven't found much evidence of any kind of life on Mars, so we scale back our expectations a bit and now are looking for evidence of life as small as bacteria, or, failing that, just conditions that might allow life to exist would make us excited. There's evidence that Mars had more water on it at one time than is in evidence now.

There may be other kinds of searches for extraterrestrials, but many of them fall below the line of being scientific.


(published on 10/22/2007)

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