Alien threat: If there are aliens, do you think they will want to conquer and colonize Earth?


British astrophysicist Stephen Hawking reignited the debate on reaching out to aliens after claiming it could be too dangerous for humans to interact with extraterrestrial life.

The 68-year-old scientist said a visit by extraterrestrials to Earth would be like Christopher Columbus arriving in the Americas, "which didn't turn out very well for the Native Americans."

He speculates most extraterrestrial life will be similar to microbes, or small animals -- but adds advanced lifeforms may be "nomads, looking to conquer and colonize."

But NASA and others argue the importance of searching for life outside our own planet outweighs the potential threat.

"The search for life is really central to what we should be doing next in the exploration of the solar system," said Cornell University planetary scientist Steve Squyres, chair of a special National Academy of Sciences panel advising NASA on future missions.

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The academy panel is looking at 28 possible missions -- from Mars to the moons of Jupiter and Saturn. And NASA is focused mostly on looking for simple life, such as bacteria, in our solar system rather than fretting about potential alien overlords coming here.

Should we continue trying to reach out to extraterrestrial life? Do the benefits outweigh the risks? Take our poll.


(This poll is not scientific. It is based on readers' votes.)