Earth-like planet discovered 600 light years away

 

 NASA’s Kepler Mission has discovered the first planet orbiting in the habitable zone of a star similar to the Sun. The planet, 600 light years away, is called Kepler 22-b.

 Earth-like planet 600 light years away with spring like temps. Astronomer Alan Boss of the Carnegie Institution of Science is in the team of researchers that discovered Kepler 22-b said:-

 Today, we have for the first time something much closer to a true Earth analog, that is a planet orbiting with a period of roughly one year around a sun-like star.

 It’s a bit bigger than the Earth. It’s about 2-2.5 times as large as our Earth is. And it certainly is orbiting at the right distance so that it could have liquid water on its surface, if it does indeed have a watery composition. The surface temperature is pretty much like a spring day on Earth, roughly 72 degrees Fahrenheit, which sounds wonderful for those of us who are rather frozen this time of the year. 

 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.

In particular it’s the habitable zone of a sun-like star. There have been previous discoveries of habitable zones, super-Earths, orbiting around M-dwarf stars. M-dwarfs are stars with masses one-tenth to one-half the mass of the sun. And that means that they’re much less luminous than the sun. That means you have to orbit much closer to the star in order to be warm enough to have liquid water.

 The planets found earlier are in at much shorter orbital periods. They’re inside, basically, the orbit of Mercury. And those are probably perfectly habitable planets, although there’s been a little bit of debate as to which ones might be habitable.

 What’s different here is again, this is a super-Earth mass planet, but for the first time it’s out at a much greater distance form the star. It’s not orbiting every thirty days, or every forty days, or sixty days; it’s orbiting every 290 days, which is very close to 365, the orbital period of the Earth.

 Planet Kepler 22-b is in our Milky Way galaxy, but far away. Light from its parent star takes 600 years to reach Earth. The evidence for Kepler 22-b are repeated observations of blinks in that star’s light, happening when the planet transits in front of the star. 

 The next step is to basically keep the Kepler Telescope up and running. It’s slated to stop functioning roughly one year from now. If it really does get that extended mission, four more years, then Kepler really will be able to measure, right down to Earth size, at Earth-like orbits. And that’s the key factor we need to understand how frequently Earth-like planets are there.