Milky Way Has 17B Planets the Size of Ours

And that's a conservative estimate
By Matt Cantor,  Newser Staff
Posted Jan 8, 2013 4:39 PM CST
Mliky Way Has 17B Planets the Size of Ours
This artist rendering released Jan. 7, 2013, by Harvard-Smithsonian Center for Astrophysics shows the different types of planets in our Milky Way galaxy detected by NASA’s Kepler spacecraft.   (AP Photo/Harvard-Smithsonian Center for Astrophysics)

Before we start feeling too special about our home planet, scientists have a message: There are at least 17 billion planets the size of Earth in the Milky Way alone, reports. About 17% of our galaxy's stars have Earth-size exoplanets closely orbiting them—so 100 billion stars in the galaxy means 17 billion such planets. And half those stars have tightly-orbiting planets that are Earth-size or larger.

That's just the beginning: Further from the stars, there are probably planets that could actually support life. "These kind of rocky objects are everywhere," says an astronomer. Indeed, the Kepler Space Telescope, which finds planets by noting stars' dimming as planets pass, found 2,700 planetary candidates in 22 months of searching—and simulations suggest that 90% of the candidates the telescope finds are in fact planets. Overall, there are likely 100 billion alien planets in our galaxy. (Read more galaxy stories.)

We use cookies. By Clicking "OK" or any content on this site, you agree to allow cookies to be placed. Read more in our privacy policy.
Get the news faster.
Tap to install our app.
Install the Newser News app
in two easy steps:
1. Tap in your navigation bar.
2. Tap to Add to Home Screen.