On Thursday (April 17), NASA announced the historic discovery of Kepler-186f, an alien planet 490 light-years from our own world that is nearly the size of Earth and located inside the habitable zone of its parent star.

The planet Kepler-186f was discovered by scientists using NASA's planet-hunting Kepler space telescope. The planet has a radius that is 1.1 times the radius of Earth, making it only slightly larger than our planet.

Main Story: Found! First Earth-Size Planet That Could Support Life
Scientists have discovered Kepler-186f, the first Earth-size alien planet in the habitable zone of its host star. See how so-called 'Earth cousin' might have water, and possibly life. Scroll down for Space.com's complete coverage of the historic find of Kepler-186f.

The rocky alien planet Kepler 186f is an Earth-size world that could have liquid water on its surface, and possibly even life. It orbits a star 490 light-years away. <a href="http://www.space.com/25526-earthsize-planet-kepler-186f-habitable-infographic.html">See the full details of alien planet Kepler-186f in this Space.com infographic</a>.
The rocky alien planet Kepler 186f is an Earth-size world that could have liquid water on its surface, and possibly even life. It orbits a star 490 light-years away. See the full details of alien planet Kepler-186f in this Space.com infographic.
Credit: By Karl Tate, Infographics Artist

Video and Multimedia

Earth-Size Planet Kepler-186f, a Possibly Habitable Alien World (Gallery)

New Earth-Size Planet Could Have Water | Video

New Earth-Size Planet and Siblings | Theoretical Animation

Exoplanet Kepler-186f: Earth-Size World Could Support  Life (Infographic)


The Search For Another Earth | Video

Alien Planet Quiz: Are You an Exoplanet Expert?

Complete Coverage:

Friday, April 18

5 Things to Know About Alien Planet Kepler-186f, 'Earth's Cousin'
Scientists recently discovered an Earth-size planet in the habitable zone of its star. Here are five things to know about the new find.

Next Up for NASA's Planet-Hunting Kepler Telescope: Finding Earth's True Twin?
NASA's planet-hunting Kepler space telescope has just spotted Earth's cousin. Its next big find may be Earth's twin.

10 Exoplanets That Could Host Alien Life

Thursday, April 17

Found! First Earth-Size Planet That Could Support Life
Scientists have discovered Kepler-186f, the first Earth-size alien planet in the habitable zone of its host star. See how so-called 'Earth cousin' might have water, and possibly life.

'Earth Cousin' Discovery a Milestone in Search for Alien Life
The search for alien life took a big leap forward with the discovery of the exoplanet Kepler-186f, the first Earth-size world ever found in the habitable zone of a star other than the sun

Op-Ed by SETI Astronomer Seth Shostak:
Cousin of Earth: Planet Kepler-186f May Be Habitable for Life (Op-Ed)

It's the brass ring that teams of astronomers from hither to yon have tried to grab: Discovering a planet that sports an environment similar to our own. Finding Earth's cousin. And now, a team of researchers may have done it.

Alien Worlds Infographic 20"x60" Poster. <a href="http://store.hermanstreet.com/space/alien-worlds-infographic-xl-print-poster-20-x60/skin-Space?ICID=Space-article">Buy Here</a>
Alien Worlds Infographic 20"x60" Poster. Buy Here
Credit: Space.com Store

5 Exoplanets Most Likely to Host Alien Life
The five far-flung worlds most likely to host life as we know it, as determined by researchers at the University of Puerto Rico at Arecibo's Planetary Habitability Laboratory.

NASA Will Unveil New Discovery from Planet-Hunting Kepler Telescope Today @ 2pm ET
NASA will announce a new discovery by its planet-hunting Kepler space telescope today, and you can following the unveiling live online. Space agency officials and scientists will host a live news teleconference at 2 p.m. EDT (1800 GMT).

Astronomers have confirmed more than 800 planets beyond our own solar system, and the discoveries keep rolling in. How much do you know about these exotic worlds?
Artist&apos;s conception of alien planets Kepler-36b and c
0 of 10 questions complete
Alien Planet Quiz: Are You an Exoplanet Expert?
Astronomers have confirmed more than 800 planets beyond our own solar system, and the discoveries keep rolling in. How much do you know about these exotic worlds?
Artist&apos;s conception of alien planets Kepler-36b and c
0 of questions complete

More Resources:

Gallery: A World of Kepler Planets

Hunting Alien Earths: Kepler Stares At Stars

Kepler Space Telescope: Exoplanet Hunter

NASA's Planet-Hunting Kepler Telescope Explained (Infographic)

Kepler Space Telescope's Alien Planet Bonanza Explained (Infographic)

Exoplanets: Worlds Beyond Our Solar System

 Follow us @Spacedotcom, Facebook and Google+.