Astronomers spot most Earth-like planet yet

Distant, rocky world similar in size to our own exists in the Goldilocks zone, where it's not too hot and not too cold
Associated Press
Apr 17, 2014


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 studies 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 find "is special because we already know that a planet of this size and in the habitable zone is capable of supporting life as we know it," lead researcher Elisa Quintana of NASA's Ames Research Center said at a news conference.

The discovery was detailed in Friday's issue of the journal Science. It was based on observations that were made before the Kepler telescope was crippled by a mechanical failure last year.

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.

Quintana 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.

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.

If the planet is habitable, photosynthesis may be possible, said astronomer Victoria Meadows of the University of Washington, Seattle.

"There are Earth plants that would be quite happy with that," she said.

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.

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 James Webb, set for launch in 2018, to study it in detail.

NASA has not yet decided whether to keep using the crippled Kepler telescope on a scaled-back basis. While the instrument may never detect another planet, scientists have a backlog of observations to wade through.



Uranus the 2nd?


In other news, Exxon dispatched a crew of intergalactic geologists to investigate the new planet.

From the Grave

"...this planet completes an orbit of its star every 130 days." 130 of our days? So, our revolution around the sun is the gauge of time throughout the vast universe. That concept is as ignorant as believing that the Earth is the center of the universe, as we once believed. What it proves is, that time does not even exist.

Don Lee

Or it's simply describing what we've been able to observe, in terms familiar to us. You might as well complain about the use of the term light-year, or its approximation into miles (which is about as silly as estimating how many inches it is to New York), in this article. You're just stuffing a straw man into a spacesuit.

Finn Finn

A discovery like this is mind-boggling. (at least with my unscientific mind!) I still can't believe men actually walked on the moon! ON THE MOON! This is a fantastic discovery!

From the Grave

What this is telling us is, that when we finish f@%&ing up OUR planet, we don't really have anywhere else to go. So we had better start taking care of this one.


I wonder how far from Kolob.


If you have your magic underwear on, should just be a days flight or so. :}

William Jeffers...

Astronomers at the University of Auckland claim that there are actually around 100 billion habitable, Earth-like planets in the Milky Way alone and there are roughly 500 billion galaxies in the universe, meaning there is somewhere in the region of 50,000,000,000,000,000,000,000 (5×1022) habitable planets, yet this is not as mind blowing as the fact that this tangible matter only constitutes 4% of the universe and the other 96% is made of Dark matter & Dark energy - of which (along with quantum gravity) remain the real mysteries of the universe.

Stop It

Wow...geek heaven in here. That's some deep s#!t.

The Hero Zone's picture
The Hero Zone

Here, I'll turn it up a notch for you: