In the great search for other earth-like planets, things have oscillated between encouraging and downright weird. So few of them seem rocky at all–mostly just gas-giants–but we’ve assumed that it’s just because the detection methods we’ve been using (gravitational wobble) are biased toward finding gas giants in close orbit.
That seems to be true. But it’s not the whole truth.
Since Kepler (the space telescope designed to detect planets) was launched, we HAVE found the occasional Earth-like planet. But it’s only occasional. Mostly we find gas giants orbiting close in (about 75% of the time). They orbit close enough in that they might actually get stripped of their atmospheres and before terrestrial planets. This might make some sense out of the recent discovery that, in order for our Solar System to form correctly, there must once have been a fifth gas giant, though that is only my guess as a layman.
When you put those discoveries together with something else, though, you run into a pretty staggering implication.
You see, it turns out that Kepler’s having some trouble because stars really do twinkle out in space. Particularly young stars–they spin faster, they’re more violent, they have weirder magnetic fields. Kepler’s job is to look for exoplanets around stars that are the same type as our Sun, but most of those stars are so damn noisy, it’s hard to get a clear picture.
Noisy stars should be even better at stripping gas giants than quiet stars, so a lot of these near-star gas giants we’re finding will, eventually, be new Earths. Hooray for noisy stars!
Noisy? Yes. Like two year olds. They’re spinning so fast, making so many sunspots, that it’s hard to see what’s around them (Kepler detects planets by looking for a particular fluctuation in brightness–when the star’s brightness is fluctuating a lot, that’s not easy to do). It’s almost as if they’re all, well, young. Our Sun, on the other hand, is very well-behaved, almost like it’s the oldest child who’s allowed to go to parties with its parents.
And if our Sun is among the oldest, it means that there are going to be lots of planets out there for us to move to when it heats up to Red Giant stage, and when it dies.
But, more importantly, if our Sun is among the oldest, we now know the answer to one of the most fundamental questions ever asked:
They’re still growing up. We’re the first (or, at least, the first ones on our block).
Since sufficiently advanced alien intelligence is indistinguishable from God, and since unless we implode or blow ourselves up we’re going to make it to other stars someday, and since some of those stars will have life forms that are a few years behind us, there’s only one thing to do: Pull out your bucket lists, boys and girls, and scratch “achieve godhood” off the list (might as well scratch off “Solve Fermi Paradox” while you’re at it). Time to get working on the next item down–interstellar travel.