An “exoplanet” is a planet outside the solar system, and today’s Google Doodle, remarkably timely (and cute), celebrates yesterday’s announcement (published in Nature; I haven’t yet read the paper) of seven exoplanets found orbiting around a single star called “Trappist-1”, forty light years away:
As NASA reports, there are seven planets, all roughly the size of Earth, though the star—their “sun”—is considerably smaller than ours (it’s about the size of Jupiter). The excitement about this announcement comes from the fact that all seven of the planets might have water in some form, but three of them are in the cushy “Goldilocks zone”, where temperatures and the presence of liquid water on a rocky planet might be amenable to the evolution of life. Here’s NASA’s depiction of the planetary system (click to enlarge):
As far as I can tell, the Spitzer infrared telescope that detected these planets didn’t actually see them; they were detected by perturbation of the signal. They will, however, be investigated more intensively with the “James Webb Space Telescope,” which will be able to detect crucial things like the presence of oxygen—almost a sure sign of life. That scope will be launched next year.
Now do these planets have any life on them? How the hell do I know? I can’t even say with any degree of certainty whether there’s life elsewhere in the Universe, though I think the odds favor it. But on these three: who knows? They’re too far away to send probes, but maybe we can now aim radio signals there, just in case there’s intelligent life.
But they’re just three planets; as Sean Carroll wrote on his Facebook page, urging caution, “Evergreen caution: the observable universe could have 10^25 planets, and the chance that any one of them has life might be 10^-100.” (That’s 0.00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000001). Still, the possibility that we’ll find life out there, which fascinates people, especially evolutionary biologists, means that we’ll cling to the smallest probabilities.
In the meantime, HuffPo, which has been driven literally insane by Donald Trump, took the opportunity to drag him into this finding. You’ll find this headline on its Science page (click on screenshot to see article), which just gives a bunch of stupid tweets. I am amused at how crazed that site has become about Trump. One would think that there’s nothing else going on in the world.