Kepler-22b: A new planet with an Earth-like orbit with a sun-like host star is discovered by Nasa
Nasa carried research hinted at the existence of near-Earth-size planets in habitable zones, but clear confirmation proved elusive. Two other small planets orbiting stars smaller and cooler than our sun recently were confirmed on the very edges of the habitable zone, with orbits more closely resembling those of Venus and Mars.
"This is a major milestone on the road to finding Earth's twin," said Douglas Hudgins, Kepler program scientist at NASA Headquarters in Washington. "Kepler's results continue to demonstrate the importance of NASA's science missions, which aim to answer some of the biggest questions about our place in the universe."
The most promising thing about this world, called Kepler-22b for now, is that it's in the so-called Goldilocks zone around its host star. Its surface temperature is estimated at an average of 72 degrees, which means liquid water -- considered essential for life as we know it -- would be possible there.
The Kepler team has done a prodigious job of detection and mathematical calculation, but Kepler has not actually seen the planet or taken any chemical measurements. They know its host star is slightly smaller and cooler than the sun, and they found that its light dims ever so slightly once every 290 Earth days. That means the dot of the planet is passing in front of it. It's a little closer to its sun than we are to our sun.
The newly confirmed planet, Kepler-22b, is the smallest yet found to orbit in the middle of the habitable zone of a star similar to our sun. The planet is about 2.4 times the radius of Earth. Scientists don't yet know if Kepler-22b has a predominantly rocky, gaseous or liquid composition, but its discovery is a step closer to finding Earth-like planets.
Kepler-22b might be the right temperature, but it is probably closer in mass to icy Neptune than to Earth. "I would bet my telescope that there is no hard, rocky surface to walk on," Marcy told the Associated Press.
Kepler-22b is located 600 light-years away. While the planet is larger than Earth, its orbit of 290 days around a sun-like star resembles that of our world. The planet's host star belongs to the same class as our sun, called G-type, although it is slightly smaller and cooler.
Alan Boss of the Carnegie Institution for Science, a colleague of Marcy's, wrote in an email to ABC News, "We know the star is sun-like, and we know the orbit is Earth-like, but the size is super-Earth-like. As Meatloaf sings, two out of three ain't bad."
The number of Earth-size and super Earth-size candidates has increased by more than 200 and 140 percent since February, respectively.
There are 48 planet candidates in their star's habitable zone. While this is a decrease from the 54 reported in February, the Kepler team has applied a stricter definition of what constitutes a habitable zone in the new catalog, to account for the warming effect of atmospheres, which would move the zone away from the star, out to longer orbital periods.
Sources:
ABC News
NASA
Nasa carried research hinted at the existence of near-Earth-size planets in habitable zones, but clear confirmation proved elusive. Two other small planets orbiting stars smaller and cooler than our sun recently were confirmed on the very edges of the habitable zone, with orbits more closely resembling those of Venus and Mars. "This is a major milestone on the road to finding Earth's twin," said Douglas Hudgins, Kepler program scientist at NASA Headquarters in Washington. "Kepler's results continue to demonstrate the importance of NASA's science missions, which aim to answer some of the biggest questions about our place in the universe."
The most promising thing about this world, called Kepler-22b for now, is that it's in the so-called Goldilocks zone around its host star. Its surface temperature is estimated at an average of 72 degrees, which means liquid water -- considered essential for life as we know it -- would be possible there.
The Kepler team has done a prodigious job of detection and mathematical calculation, but Kepler has not actually seen the planet or taken any chemical measurements. They know its host star is slightly smaller and cooler than the sun, and they found that its light dims ever so slightly once every 290 Earth days. That means the dot of the planet is passing in front of it. It's a little closer to its sun than we are to our sun.
The newly confirmed planet, Kepler-22b, is the smallest yet found to orbit in the middle of the habitable zone of a star similar to our sun. The planet is about 2.4 times the radius of Earth. Scientists don't yet know if Kepler-22b has a predominantly rocky, gaseous or liquid composition, but its discovery is a step closer to finding Earth-like planets.
Kepler-22b might be the right temperature, but it is probably closer in mass to icy Neptune than to Earth. "I would bet my telescope that there is no hard, rocky surface to walk on," Marcy told the Associated Press.
Kepler-22b is located 600 light-years away. While the planet is larger than Earth, its orbit of 290 days around a sun-like star resembles that of our world. The planet's host star belongs to the same class as our sun, called G-type, although it is slightly smaller and cooler.
Alan Boss of the Carnegie Institution for Science, a colleague of Marcy's, wrote in an email to ABC News, "We know the star is sun-like, and we know the orbit is Earth-like, but the size is super-Earth-like. As Meatloaf sings, two out of three ain't bad."
The number of Earth-size and super Earth-size candidates has increased by more than 200 and 140 percent since February, respectively.
There are 48 planet candidates in their star's habitable zone. While this is a decrease from the 54 reported in February, the Kepler team has applied a stricter definition of what constitutes a habitable zone in the new catalog, to account for the warming effect of atmospheres, which would move the zone away from the star, out to longer orbital periods.
Sources:
ABC News
NASA
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