The "Great Filter" is a hypothetical barrier to explain why civilisations are so unlikely to progress to the point of inter-stellar colonisation that we have not encountered any in 40 years of looking. Maybe humanity has already negotiated the filter - as some massive evolutionary improbability - or perhaps it lies in our future as an almost-certain threat to our existence? We should hold our breath as we look for evidence of life on Mars.
posted by rongorongo on May 12, 2008 - 85 comments

Fears that malevolent aliens will tune into this week's broadcast of The Beatles' song "Across the Universe" have been voiced by scientists.
posted by monospace on Feb 7, 2008 - 68 comments

The first was found just fifteen years ago, after centuries of speculation. As of today, we're up to 227 and counting. Most are just wobbles in data, but we have pictures and exotica too. And we are looking for more (although some think we shouldn't look very hard and others are drawing some surprising conclusions). The science and technology of finding the most fascinating and elusive types demands some of the cleverest engineering, yet you can even have a go for yourself. Previously on Metafilter
posted by Devonian on Apr 22, 2007 - 23 comments

[x] ok to transmit this posting into outer space (via space.craigslist.org)
posted by loquacious on Feb 28, 2005 - 9 comments

ET Could Hack SETI. SETI, which uses down time on the computers of thousands of volunteers to search for intelligent signals from space, has a potential problem—besides information, a broadcast to us from an alien intelligence could also carry a computer virus. Leonard David writes in the main link's space.com article that physicist Richard Carrigan (who works here) takes it seriously. He thinks SETI should figure out how to decontaminate any signals it receives.
posted by jasonspaceman on Nov 24, 2003 - 35 comments