New Earth-like Planet Discovered

Last Thursday NASA called a press conference. It was a bit out of the blue but we were given a heads up that it had to do with Kepler so everyone knew they would be announcing a newly discovered earth-like planet; and so it came to be. Kepler, of course, was the planet hunting satellite named after Johannes Kepler the German mathematician and astronomer. Kepler worked using the transit method; it would stare at thousands of suns and look for tiny dips in the levels of brightness, this could indicate that a planet had passed in front of, or transited, the star and temporarily blocked some of its light. If a dip was found to have a regular pattern then there was a good chance it was a planet. Using this method Kepler has found many thousands of candidate planets, 1879 of which have been confirmed at time of writing.

Thursday's announcement of planet Kepler 452b was a little different as they claimed to have found the exoplanet most like our own. The planet is a rocky one about 60% larger in size than the earth but about 5 times more massive, so it's likely to be very volcanic with quite a dense atmosphere. Its sun is 50% or so larger than our own and a billion years older so it's likely to throw out a lot more heat than we're used to experiencing. This combination could actually mean that conditions on the planet are too harsh for life to exist, certainly complex life anyhoo.

Before this announcement the most earth-like planet discovered to date was Kepler 186f. This is a rocky world no more than 10% larger than us orbiting a red dwarf star. Even at midday this world would only be about as light as sunset here on earth, despite this I think 186f actually remains the most earth-like planet we have yet discovered. Sorry Kepler 452b.

Below you can see the four most earth-like planets and their stars discovered by Kepler so far with the earth for comparison.

Image courtesy of NASA