NASA has announced the first-ever discovery of an Earth-size planet that could hold liquid water, which is basically the same as NASA announcing that they've found an Earth-like planet that could be the site of Earth-like life. That's right you guys, aliens.
Quintana: Kepler-186F is closest to Earth in size. It's the first planet we've found that may be habitable. http://t.co/M25i2hLYYw— NASA (@NASA) April 17, 2014
BREAKING. Astronomers confirm discovery of first rocky, Earth-sized planet that might hold liquid water--necessary ingredient for life.— Charlie Kaye (@CharlieKayeCBS) April 17, 2014
The planet, Kepler-186f, was discovered by NASA's Kepler mission and is within its star's habitable zone. Although scientists don't know the density of the object -- or its age -- they suspect it is rocky with a stronger gravitational pull than we feel on Earth. According to NASA scientist Tom Barclay, the find is major. He writes for ITV.com:
The habitable, or 'Goldilocks', zone is the region around a star within which a planet can sustain liquid water on its surface given the right atmospheric conditions... We built and launched the Kepler spacecraft to find planets such as this. This day is a momentous one. We now know that there are Earth-sized planets in habitable zones of other stars.
NASA offers some more information in a press release:
The discovery of Kepler-186f confirms that planets the size of Earth exist in the habitable zone of stars other than our sun. While planets have previously been found in the habitable zone, they are all at least 40 percent larger in size than Earth and understanding their makeup is challenging. Kepler-186f is more reminiscent of Earth.
Kepler-186f is one of five planets circling the star Kepler 186, which is smaller than our sun. It's not exactly like Earth:
The new exoplanet, Kepler-186f, is more like an Earth in a Marslike orbit. Gets 1/3rd the radiation Earth does.— Alexandra Witze (@alexwitze) April 17, 2014
Meadows: We have no definitive evidence that shows a possible atmosphere on this planet. http://t.co/M25i2hLYYw— NASA (@NASA) April 17, 2014
But it's close. According to NASA , we still have a long way to go in looking for alien life:
The next steps in the search for distant life include looking for true Earth-twins -- Earth-size planets orbiting within the habitable zone of a sun-like star -- and measuring the their chemical compositions.
But today we're one step closer.