This diagram compares our own solar system to Kepler-22, a star system containing the first “habitable zone” planet discovered by NASA’s Kepler mission. The habitable zone is the sweet spot around a star where temperatures are right for water to exist in its liquid form. Liquid water is essential for life on Earth.
Kepler-22’s star is a bit smaller than our sun, so its habitable zone is slightly closer in. The diagram shows an artist’s rendering of the planet comfortably orbiting within the habitable zone, similar to where Earth circles the sun. Kepler-22b has a yearly orbit of 289 days. The planet is the smallest known to orbit in the middle of the habitable zone of a sun-like star. It’s about 2.4 times the size of EarthKepler-22B may be the most Earth-like world yet found in the galaxy. It orbits a star like the Sun 600 light years — that is nearly 4,000 billion miles away in the constellation Cygnus.
NASA’s new finding, Kepler-22b may support life and vegetation. It may take decades or centuries in making things more clear about Kepler-22B.
Kepler-22B joins a list of more than 500 planets found to orbit stars beyond our solar system. It is the smallest and the best positioned to have liquid water on its surface – among the ingredients necessary for life on Earth. It is 2.4 times the size of the Earth, putting it in a class known as “super-Earths”.
“We have now got good planet confirmation with Kepler-22B,” said Bill Borucki, Kepler principal investigator at NASA Ames Research Center. “We are certain that it is in the habitable zone and if it has a surface, it ought to have a nice temperature,” he said.
This is the first detection of a potentially habitable world orbiting a Sun-like star, scientists reported in findings to be published in The Astrophysical Journal. Kepler-22B is 600 light years away. A light year is the distance light travels in a year, about 10 trillion km.
Kepler-22B sits squarely in its star’s so-called “habitable zone,” the region where liquid water could exist on the surface. Follow-up studies are under way to determine if the planet is solid, like Earth, or more gaseous like Neptune.
“We don’t know anything about the planets between Earth-size and Neptune-size because in our solar system we have no examples of such planets. We don’t know what fraction is going to be rocky, what fraction are going to be water worlds, what fraction are ice worlds. We have no idea until we measure one and see,” Batalha said at a news conference at NASA Ames Research Centre in Moffet Field, California.
If Kepler-22B has a surface and a cushion of atmosphere similar to Earth’s, it would be about 22 deg C, about the same as a spring day in Earth’s temperate zone.
The planet’s first “transit”, or star crossover, was captured shortly after NASA launched its Kepler spacecraft in March 2009. Kepler is NASA’s first mission in search of Earth-like planets orbiting suns similar to ours, and cost the US space agency about $600 million.
NASA announced that Kepler has uncovered 1,094 more potential planets, twice the number it previously had been tracking.
Source: NASA and truthdive