To follow up this, Charles Stross asks how habitable Earth is: I want you to imagine that, instead of being a perplexed mostly-hairless primate reading a blog, you're the guiding intelligence of an interstellar robot probe. ...Your first destination planet is the cloud-whorled third planet out from an undistinguished G2 star, orbited by an airless, tidally-locked moon with roughly 1.3% of the planet's own mass.
...However, the Earth is a lot more than 200 kiloyears (Ky) old; the surface formed roughly 4.6 Gy ago (gigayears — 1Gy = 1,000,000,000 years). And we can expect the Earth to persist for about another 3-5 Gy, until the sun leaves the main sequence of the Hertzsprung-Russell diagram and becomes a red giant, presumably swallowing the Earth (or at any rate rendering it too crispy for comfort). So if we're being honest (and not cherry-picking our candidate stellar colony mission targets) we've got a 8-10Gy span to probe.
...The point to take away from this is that, between T minus 4.6 Gy and T minus 0.56 Gy, the Earth's atmosphere was largely free of oxygen. ...Even after the oxygen catastrophe, our space probe isn't going to find a terribly hospitable planet.
Best to find a more habitable planet elsewhere, really.
Stross also discovers why the later Star Treks are so terrible: former Star Trek writer and creator of the re-imagined Battlestar Galactica Ron Moore revealed the secret formula to writing for Trek. He described how the writers would just insert "tech" into the scripts whenever they needed to resolve a story or plot line, then they'd have consultants fill in the appropriate words (aka technobabble) later.
Which I suppose makes this the appropriate place to linkdump Star Trek Mark Two and Brain Bugs, as well as David Brin's war on "Star Wars" (1, 2, 3). And all the evidence we need that the Weekly Standard would be rooting for the Empire.