
As they develop some technological sophistication, they begin to understand the nature of planets, and begin to use telescopes to learn more about their orbital companion. They see that it is a world much like their own with what appear to be mountains, deserts and seas, but their telescopes are primitive and they cannot make out more details, and they have no way of traveling there.

Oh, wait, that’s not fiction. That’s Earth’s history. The other planet is our moon, which is big enough to be considered a planet in its own right. (It is big enough that if the Earth wasn’t there, the moon would still be able to dominate that orbit on its own, thus meeting the modern IAU definition of “planet.”) And in fact Earth and its moon are close enough in size that many consider them to be a double-planet.
So the next time you look out your window at night, don’t just casually note the light of the moon. Marvel at the fact that there’s a whole freaking planet hanging right there in the sky. (Tonight's a good night to look: there's a full planet!)
It’s close enough that when we build permanent settlements there, we’ll be able to see the lights, just like they’ll see ours. It’ll be pretty hard not to think of it as another planet at that point.
No comments:
Post a Comment