From the Bad Astronomer's blog:

http://www.badastronomy.com/bablog/2008/01/16/no-alien-signal/

No alien signal

Posted at 3:01 pm in Astronomy, Debunking, Science, Skepticism

OK folks, nothing to see here.

I talked with my buddy Seth Shostak, who is a Senior SETI astronomer, and he told me that this whole alien signal thing is a big misunderstanding on the part of the KTVU reporter.

Basically, Dan Wertheimer, a radio astronomer who is affiliated with SETI, detected a pulse from space. The source is certainly extragalactic, and is most likely some sort of natural event. It’s unclear exactly what kind of event, but there is a long list of things it could be. Aliens phoning us is pretty far down that list. But since Dan does do some SETI work, the reporter just botched things up a bit and misattributed the source. The news article reads oddly, like he took a mishmash of topics and wrote them all up into one article, so this misunderstanding doesn’t surprise me much.

The signal was detected quite some time ago, and had it been alien, believe me you would have heard from the folks at SETI!

So chalk this one up as yet another in a long line of false alarms. Sorry to burst the ET bubble.