The planets are likely the right size and right temperature to support complex life. The Kepler planet-searching telescope has detected nearly 50 such planets in one small part of the observable universe.
Image: Imago/UIG
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NASA said Monday its Kepler Space Telescope mission discovered 10 new rocky, Earth-like planets outside of our solar system which could support life.
"Are we alone? Maybe Kepler today has told us indirectly, although we need confirmation, that we are probably not alone," said Kepler scientist Mario Perez.
Those 10 planets were orbiting suns at a similar distance to Earth's orbit around the sun. This distance is considered the "Goldilocks Zone" - not too close, not too far away from the sun, just right to support life.
Seven of these planets were circling stars similar to our sun. This does not mean life of any complexity has been found on these planets, but the chances that Earth is the only planet that supports life are dwindling.
"It implies that Earth-size planets in the habitable zone around sun-like stars are not rare," Harvard astronomer Avi Loeb wrote in an email to the AP news agency. Loeb was not part of the Kepler research team.
Kepler also discovered 209 other planets, scientists announced Monday.
More planets than expected
The Kepler telescope has detected nearly 50 planets in the Goldilocks Zone in four years of searching. The Kepler telescope only looked at a small part of the Milky Way galaxy. The telescope studied about 150,000 stars, while the Milky Way contains hundreds of billions of stars.
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Before Kepler was launched in 2009, astronomers hoped there would be Earth-like planets around about 1 percent of stars. Scientists involved with the Kepler telescope said that number is closer to 60 percent this weekend.
"This number could have been very, very small," said Caltech astronomer Courtney Dressing.
"I, for one, am ecstatic."
The Kepler telescope will soon make way for its successor. The Transisting Exoplanet Survey Satellite (TESS) will observe the brightest 200,000 nearby stars for two years starting next year.
The James Webb Space telescope, which will replace the Hubble telescope next year, will be able to detect the make-up of atmospheres of exoplanets. The James Webb telescope will also be able to determine the possibility of finding potential life forms.
kbd/rc (AFP, AP, Reuters)
Meet the planets
The first close-ups of Pluto awed the world this week. A couple of decades ago, photos of Venus or Saturn taken from space had a similar effect on scientists. Join DW on an interplanetary photo safari!
Image: Reuters/NASA/APL/SwRI/Handout
Our solar system
Depending on who you ask, there are eight or nine planets in our solar system - some experts still count Pluto, while the International Astronomical Union (IAU) took away its planetary status in 2006. People were still excited when NASA presented the first high-res images of Pluto this week. Its neighbors all had their portrait taken as early as the 1960s.
Mercury
The spacecraft Mariner 10 left for the planet closest to the Sun in 1973. It took this picture of Mercury's moon-like surface in March 1974. The planet's distance to the Sun varies between 28.5 million miles (46 kilometers) and 43.5 million miles (70 kilometers), because its orbit isn't a perfect circle. Scientists were surprised to discover that Mercury had a small magnetic field.
Image: picture-alliance/dpa/Nasa
Venus
Mariner 10 took this first close-up of Mercury's direct neighbor on February 5, 1974. The picture was color-enhanced by NASA to bring out Venus' cloudy atmosphere - the planet is perpetually blanketed by a thick veil of clouds rich in carbon dioxide. Mariner 10's journey to Venus was a rocky one: the spacecraft's high-gain antenna developed problems and a mechanical issue caused a large fuel-loss.
Image: picture-alliance/dpa/Nasa
Earth
The first full-on photo of our planet as seen from outer space was taken by Lunar Orbiter 1 in August 1966. That was three years before a human being had ever set foot on the Moon, which can be seen in the foreground of this picture as a shadow. The now-iconic photo was one of a series of pictures taken in preparation for the Apollo missions that would eventually put a human on the Moon.
Image: picture-alliance/dpa/Nasa/Loirp
Mars
This close-up of Earth's neighbor is the first picture ever taken of another planet by a spacecraft. Mariner 4 snapped it on July 15, 1965. Scientists who had expected to see lakes, valleys and mountains were disappointed - instead of an Earth-like planet, they were treated to craters similar to those on the Moon. The New York Times wrote: "Mars is probably a dead planet."
Image: picture-alliance/dpa
Jupiter
Spacecraft Pioneer 10 took the planet's first close-up from roughly 80,780 miles (130,000 kilometers) away on November 19, 1973. Jupiter is our solar system's largest planet. At its equator, Jupiter's diameter is a whopping 88,846 miles (142,984 kilometers). Its mass is two-and-a-half times larger than the masses of all other planets combined.
Image: picture-alliance/dpa/UPI
Saturn
This first shot of the ringed planet was taken on Pioneer 10's follow-up mission, Pioneer 11, on August 31, 1979. It was a perilous adventure: as the spacecraft flew through Saturn's outer rings, it almost crashed into one of two new moons it discovered. Visible at the upper left-hand corner in this photo is Saturn's moon Titan.
One of the first glimpses scientists got of Uranus was of its rings. Voyager 2 took this shot of them in 1986. Scientists had to remote-fix the spacecraft's camera for it to be able to photograph the planet with the coldest atmosphere in our solar system (as low as -366 degrees Fahrenheit or -221 degrees Celsius). The device had malfunctioned while Voyager 2 was passing Saturn.
Image: picture-alliance/dpa/Consolidated
Neptune
Voyager 2 also took the first picture of Neptune in August 1989. The planet has four cloud features that scientists know about. For those who don't count Pluto, Neptune is the planet in our solar system that's furthest away from the sun: at an average of 2.8 billion miles (4.5 billion kilometers), that distance is 30 times greater than the one between the Sun and Earth.
Image: picture-alliance/dpa
Pluto
The fact that Pluto is not officially a planet anymore didn't detract from the excitement scientists and lay-people all over the world experienced when NASA released this first close-up of the copper-colored (dwarf-) planet taken by New Horizons on July 13, 2015. The spacecraft traveled 3 billion miles (4.88 billion kilometers) to the solar system's farthest reaches for this shot.
