Tonight's Sky
Sun
Sun
Moon
Moon
Mercury
Mercury
Venus
Venus
Mars
Mars
Jupiter
Jupiter
Saturn
Saturn

Tonight's Sky — Change location

OR

Searching...

Tonight's Sky — Select location

Tonight's Sky — Enter coordinates

° '
° '

What impact has the Kepler space telescope's exoplanet discoveries had on the Drake equation?

Jeff Fleenor, Pella, Iowa
RELATED TOPICS: MILKY WAY
Equation
For millennia, we humans have looked up at the night sky and wondered if, out there, there are other worlds like our own, and if, on some of those worlds, there are other beings that wonder as we do.

One tool to address this question is the Drake equation, which lays out the quantities needed to estimate the number of intelligent civilizations in the Milky Way Galaxy. I’ll define an intelligent civilization as one capable of communicating over interstellar distances. Our species has had this capability for less than a century.

NASA’s Kepler space telescope has completely altered our view of planets beyond the solar system. The mission has shown, among other things, that as many as one in five Sun-like stars harbors an Earth-sized planet residing in the “habitable zone,” the range of orbital distances where liquid surface water could plausibly exist. There are roughly 200 billion stars in the Milky Way Galaxy, of which a quarter are Sun-like. So there are about 10 billion potentially habitable planets around Sun-like stars in the Milky Way alone. Prior to Kepler, Fp was entirely unconstrained. With Kepler, astronomers have measured Fp, at least roughly. Uncertainties remain for several reasons: The boundaries of the habitable zone are uncertain, Kepler has only probed a narrow slice of the galaxy, and there are likely other necessary conditions for life besides surface liquid water. I am hopeful that, in my lifetime, we will launch telescopes capable of imaging distant Earth-like worlds and “sniffing” their atmospheres to look for signs of alien life.
Erik Petigura
University of California, Berkeley
0

JOIN THE DISCUSSION

Read and share your comments on this article
Comment on this article
Want to leave a comment?
Only registered members of Astronomy.com are allowed to comment on this article. Registration is FREE and only takes a couple minutes.

Login or Register now.
0 comments
ADVERTISEMENT
FREE EMAIL NEWSLETTER

Receive news, sky-event information, observing tips, and more from Astronomy's weekly email newsletter. View our Privacy Policy.

ADVERTISEMENT
ADVERTISEMENT
Apollo_RightRail
A chronicle of the first steps on the Moon, and what it took to get there.
Find us on Facebook