nb_cid nb_clickOther -tt-nb this.style.behavior='url(#default#homepage)';this.setHomePage('http://www.aol.com/?mtmhp=acm50ieupgradebanner_112313 network-banner-empty upgradeBanner
Search AOL Mail
AOL Mail
AOL Favorites

Astronomers spot Kepler-186f, the most Earth-like planet yet

LOS ANGELES (AP) -- Astronomers have discovered what they say is the most Earth-like planet yet detected - a distant, rocky world that's similar in size to our own and exists in the Goldilocks zone where it's not too hot and not too cold for life.

The find, announced Thursday, excited planet hunters who have been scouring the Milky Way galaxy for years for potentially habitable places outside our solar system.

"This is the best case for a habitable planet yet found. The results are absolutely rock solid," University of California, Berkeley astronomer Geoff Marcy, who had no role in the discovery, said in an email.

The planet was detected by NASA's orbiting Kepler telescope, which examines the heavens for subtle changes in brightness that indicate an orbiting planet is crossing in front of a star. From those changes, scientists can calculate a planet's size and make certain inferences about its makeup.

The newfound object, dubbed Kepler-186f, circles a red dwarf star 500 light-years from Earth in the constellation Cygnus. A light-year is almost 6 trillion miles.

The planet is about 10 percent larger than Earth and may very well have liquid water - a key ingredient for life - on its surface, scientists said. That is because it resides at the outer edge of the habitable temperature zone around its star - the sweet spot where lakes, rivers or oceans can exist without freezing solid or boiling away.

The planet probably basks in an orange-red glow from its star and is most likely cooler than Earth, with an average temperature slightly above freezing, "similar to dawn or dusk on a spring day," Marcy said.

The discovery was detailed in Friday's issue of the journal Science.

Lead researcher Elisa Quintana at NASA's Ames Research Center said she considers the planet to be more of an "Earth cousin" than a twin because it circles a star that is smaller and dimmer than our sun. While Earth revolves around the sun in 365 days, this planet completes an orbit of its star every 130 days.

"You have a birthday every 130 days on this planet," she said.

Scientists cannot say for certain whether it has an atmosphere, but if it does, it probably contains a lot of carbon dioxide, outside experts said.

"Don't take off your breathing mask if you ever land there," said Lisa Kaltenegger, a Harvard and Max Planck Institute astronomer who had no connection to the research.

Despite the differences, "now we can point to a star and know that there really is a planet very similar to the Earth, at least in size and temperature," Harvard scientist David Charbonneau, who was not part of the team, said in an email.

Since its launch in 2009, Kepler has confirmed 961 planets, but only a few dozen are in the habitable zone. Most are giant gas balls like Jupiter and Saturn, and not ideal places for life. Scientists in recent years have also found planets slightly larger than Earth in the Goldilocks zone called "super Earths," but it is unclear if they are rocky.

The latest discovery is the closest in size to Earth than any other known world in the habitable region.

Kepler-186f is part of a system of five planets, all of which are roughly Earth's size. However, the other planets are too close to their star to support life.

Astronomers may never know for certain whether Kepler-186f can sustain life. The planet is too far away even for next-generation space telescopes like NASA's overbudget James Webb, set for launch in 2018, to study in detail.

Kepler completed its prime mission and was in overtime when one of the wheels that keep its gaze steady failed last year. NASA has not yet decided whether to keep using the telescope to hunt for planets on a scaled-back basis.


AP Science Writer Seth Borenstein contributed to this report.

Join the discussion

1000|Char. 1000  Char.
sirdragonwolf April 17 2014 at 3:09 PM

Great, lol!!!; first how does man get there (we do probably have the technology, for the most part... scary thought...) if it was uninhabited how fast would it be destroyed with pollution, nuclear waste, murder, genocide, war, violence, etc., etc., etc., ... We have not even remotely come close to living together as a true human race here! Not a good thing! If there are other intelligent life forms, more advanced; do you think that they would let us get there... LOL

Flag Reply +1 rate up
3 replies
lflz28 April 17 2014 at 3:41 PM

Hello fellow earthlings, I see you have found us. We would like to extend our congratulations After Planting our Human seed 20,000 years ago on the planet you now call EARTH we expected you to find us 5000 years sooner but you fell into that Fear of knowing thing. We are so happy you are awake now see you again soon. Yes That is our spacecraft you are calling UFOs Oh and to answer your other question WE built the Pyramids 30,000 years ago as power supply units for our mother ship landings. Would you please put them in working order again?? We would like to visit again soon..

Flag Reply +3 rate up
landslowrance April 17 2014 at 9:51 PM

WOW that's good to hear. Now, let's figure out how to do a manned mission to Mars and back.

Flag Reply +1 rate up
ftuna2u2 April 18 2014 at 2:16 AM

Somebody please teach me how to disable whatever it is that makes ads and other videos play automatically.

Flag Reply +2 rate up
3 replies
Len April 17 2014 at 3:16 PM

They will find second Earths much closer to us. My money is on the Alpha Centauri system. There are three stars in the system and three "life" or "goldilocks" zones. They have already found one planet, a super Earth called Bb. Past study has shown that when the first planet discovered in a solar system is a Super Earth, it will be accompanied by a flock of other smaller planets and at least one of them will be in the life zone.

What I know is that if we were residing in the Alpha Centauri system with as many as six other planets supporting organic life, we would already be space faring, even to tiny Proxima. And, since the nearest star to us is only 16 times further away than Proxima is from Alpha and Beta Centauri and it has two planets in its life zone, we would visit Earth sooner rather than later.

My guess is that Alpha Centauri has a civilization and that civilization has visited us. Possibly even now.

Flag Reply +1 rate up
1 reply
ferrariqx Len April 17 2014 at 3:21 PM

The Earth has NEVER been visited by an Alien civilization. Alien civilizations have the same problem we do. The distances are too great to travel in a reasonable period of time. Thousands of years for traveling between solar systems isn't practical for any species.

Flag Reply +1 rate up
dorc792 April 17 2014 at 3:16 PM

turn that probe that found this planet to ocean to find plane...or where ever it is...

Flag Reply +3 rate up
ksokol3171 April 17 2014 at 9:53 PM

How about forsaking war in our planet before we try another planet?

Flag Reply +4 rate up
1 reply
lflz28 ksokol3171 April 17 2014 at 10:21 PM

Can you imagine what the population would be if we did not have wars to control it...

Flag Reply +1 rate up
laceylujonesj April 17 2014 at 3:16 PM

WHAT A FIND. hope they find out more

Flag Reply +2 rate up
paddleman1928 April 17 2014 at 9:54 PM

human stupidity-we look for a place to live when we HAVE a place to live.

Flag Reply +1 rate up
1 reply
anteekazoid paddleman1928 April 18 2014 at 12:36 AM

Some of us are trying to get away.

Flag Reply 0 rate up
csands4 April 18 2014 at 1:49 AM

rocky landscape... average temperature just above freezing... a lot of carbon dioxide...they just discovered North Dakota

Flag Reply +6 rate up
1 reply
jmg62 csands4 April 18 2014 at 4:31 AM

Nah, sorry csands - that's the re-discovery of the Meadowlands in New Jersey. Those rocks are the decaying dead bodies tossed in the 1950's-60's from the Mob. Probably the smell that fooled 'em. More sulfurry - rotten egg smell. Makes a fog like deadly gas that they let the Sun burn off in the mornings since no open flames are allowed! ;)

Flag Reply 0 rate up
aol~~ 1209600


More From Our Partners