Actually, what I’m about to discuss is the search for ET life, but you have to start somewhere and it’s getting more clear by the day that alien intelligence is the best hope for us blog denizens to find someone to talk to.
The idea that we’re not alone has a long and fascinating history, going back to Giordano Bruno [1] who got burned at the stake for it. By the time SETI [2] came along, things had advanced from that point. But not too far. You pretty much got burned at the academic stake for being involved in it, if they could get at you, so the field was heavily populated with tenured professors. By now, the astronomers have found so many planets orbiting other stars (including one, maybe more, exoplanets with evidence of water [3]!) that scientists have gone from thinking SETI was for kooks to looking for the life-bearing planets they know are out there.
Just recently, March 9th to be precise, an article came out [4] with such an elegant method of checking for life that we may be hearing about the first find in a matter of years instead of centuries. Life is peculiar in that it prefers molecules that polarize light a certain way (technically termed chirality). Whether or not light is polarized can be seen right across the universe, and whether that polarization has a given chirality or not, likewise.
[5]
The only problem is that we’re talking about very, very, very faint light here. The light has to bounce off, or pass through the atmosphere of a life-bearing planet before it acquires that signature polarization. Passing through gives the brightest signal, but for that the planet has to transit in front of its parent star, from our perspective, when for two brief moments (coming and going) the star shines through the planet’s atmosphere. That’s a somewhat rare event, and we don’t have too many candidates to check yet, but we do already have the capability to see the signal if we get it.
They could be looking at, for instance, Gliese 581e [6] in the next few months. We might actually know any day now that there’s life besides ours among the stars. Being a total nerd, I’m wildly excited and waiting with bated breath. What do you think? Fun, huh?