Have we found another planet Earth?

2011-12-07 Vatican Radio

About 600 light-years from Earth, Kepler 22-b is not close to home, it doesn’t have a very romantic name and while scientists are not yet sure if it is made mostly of rock, gas or liquid, it does have similarities to our own – making it the latest best potential for a life sustaining planet. On Monday NASA said ithe Kepler space telescope has confirmed its first-ever planet in a habitable zone outside our solar system. Kepler-22b, initially glimpsed in 2009, is the first the US space agency has been able to confirm. “We’ve got a star that’s like the sun, with a planet that is like earths size, in an orbit that is like earth’s orbit” says Br. Guy Consolmagno, astronomer and planetary scientist at the Vatican Observatory. “All of this is telling us that it could be a planet that has conditions, just the right amount of heat, just the right amount of sunlight to make life possible and it’s the first one that we have really got that matches all the details we are looking for”. Confirmation, AS Br. Consolmagno explains, means that astronomers have seen the planet crossing in front of its star three times: “The Kepler Telescope is aimed at a specific and very rich patch of stars to look for very slight variations in the starlight”. “They have managed to see this [the star] dim and come back three times, they have got the period down and they know what the mass of the star is because of the type of the star, it is very similar to our sun, and the period of the variations is about 300 days, which is typical of an earth year. Plus, the amount that the star has dimmed with this planet crossing in front of it they can figure out how big it is and only about twice the radius of the earth”. Listen to Emer McCarthy’s full interview with Br. Consolmagno: