So Much for Earth Being Special: There Could Be 20 Billion Just Like It
The planet-hunting Kepler Space Telescope is deservedly celebrated for some of its more dramatic discoveries: a world with two suns, for example, a planet half-shrouded with clouds, a planet whose size and composition are a near match to Earth’s. But the ship is in some ways a pretty prosaic machine — a robot census taker, no more, no less, hanging in space and counting heads, to determine how many stars other than our own are home to planets. Like a census taker too, however, it has to make some pretty elaborate inferences.
It’s not possible to detect and count every single planet in the Milky Way, any more than it’s possible to shake the hand and take the name of every single person living in the U.S. In both cases, a sort of statistical sampling is often involved. When you know enough about most of the…
View original post 879 more words