Scientists analyzing data from the Kepler space telescope announced last week that they had confirmed almost 1,300 new planets orbiting different stars in our galaxy. That figure represents the ones they are 99+% certain are planets, with another 1,300 or so "more likely than not" to be planets.
Because of the vast distances and the high possibility of even small observing glitches affecting the outcome, the 99% threshold is the minimum bar a potential planet finding has to reach to be considered a planet. By that yardstick, I never took astronomy in college. Or most of my other classes either, come to think of it.
Although it seems commonplace to us today, the idea that other stars have planets was an open question not many years ago. And some theories of planetary formation over the past few centuries were oddball enough to suggest there might be very few planets outside of our own solar system. But the adoption of the nebular hypothesis as the most likely explanation for how stars and planets form, combined with Kepler's observations, mean that stars with planets may be more likely than stars without planets.
Now if I could only find a way to get to one of them before November 8.