In Milky Way, planets more plentiful than stars
The more astronomers look for other worlds, the more they find that it’s a crowded and crazy cosmos. They think planets easily outnumber stars in our galaxy and they’re even finding them in the strangest of places.
And they’ve only begun to count.
Three studies released Wednesday, in the journal Nature and at the American Astronomical Society’s conference in Austin, Texas, demonstrate an extrasolar real estate boom. One study shows that in our Milky Way, most stars have planets. And since there are a lot of stars in our galaxy — about 100 billion — that means a lot of planets.
“We’re finding an exciting potpourri of things we didn’t even think could exist,” said Harvard University astronomer Lisa Kaltenegger, including planets that mirror “Star Wars” Luke Skywalker’s home planet with twin suns and a mini-star system with a dwarf sun and shrunken planets.
NASA’s new Kepler planet-hunting telescope in space is discovering exoplanets that are in a zone friendly to life and detecting planets as small as Earth or even tinier. That’s moving the field of looking for some kind of life outside Earth from science fiction toward just plain science.