Jill Tarter and the Allen Telescope Array

An anonymous reader writes "Today's interview with Jill Tarter of the SETI Institute (and Carl Sagan's inspiration for the main character of his novel Contact), outlines the forthcoming search capabilities of the large Allen Telescope Array. Their thousand-fold expanded search must find promising places to point 350 radio dishes. Outside San Francisco, the array spans an equivalent 8 football fields. Their new catalog, called HabCat, identifies all potentially habitable hosts for complex life within 450 light-years from Earth. Of the billions of places to point in the sky, their A-list total: 17,129. Start at Vega."

Comments

All this effort is going on the wrong planet

[bcollier06]

Wouldn't it be much more likely that a society advanced enough to be detectable across the vast reaches of interstellar space would find humans based upon primitive radio frequency transmissions? We might be able to just kick back and hope for our sake they don't take any of those hitler or vietnam broadcasts too seriously...

While the possibility of extra-terrestrial life is a fascinating one, aren't there a lot more equally fascinating yet infinitely more practical aspects of space exploration to spend tons of money on?

Divine Intervention

[kevlar]

Would you consider yourself a determined believer that extra-terrestrials exist? If (for the sake of discussion) you were to determine that we were, without a doubt the only life in the Universe, how would that impact any religious beliefs you may hold?

I personally believe that if we were to be the only life in the Universe that this would be divine intervention simply because of the statistics, would you agree?

What else would you suggest?

[robinw]

Actually, there are more assumptions made than that. They are assuming that the lifeforms have developed radio technology as a form of communication, which could also be seen as an evolution of the ears/mouth that we have.

Really, though, what it comes down to is this - the universe is REALLY, REALLY, REALLY big. And the amount of time they have to scan it is REALLY, REALLY, REALLY small. So what they're doing is deciding which planets to scan first. Since we have no idea what other platforms that life could have evolved on, the safest bet is to use that short amount of time is to scan those which are similar to our own. The idea being that we DO know what kind of variables were able to sustain life here.

In the future, I think you'll see they'll expand their searching, as technology improves and our understanding increases.

Re:In some ways, the catalog is a waste of time.

[Glock27]

It assumes that other life on other planets would be humanlike and thus need a similar environment.

There is more to it than that. Biochemists have done substantial analysis regarding what other chemical families might support life. It looks as though with the periodic table as it is, carbon is the only good choice for rich biochemistry. For carbon life to develop, liquid water appears necessary. So, you have narrowed the search volume considerably by only considering stars that would likely have a planet in the "liquid water" sweet spot, while not getting fried by hard radiation at the same time.

Further, a planet must exist long enough for evolution to occur. That eliminates a great number of stars as well - many just don't last long enough.

As another poster pointed out, that at least provides a starting point on where to look.