Earth Sized Planet Near Alpha Centauri
European astronomers have discovered a planet that resembles the Earth in both size and mass. The planet orbits Alpha Centauri B the nearest star to our own. It is part of a triple star system and is just 4.3 light years away.
In relative terms the new planet is 4.3 trillion miles from Earth, but that is incredibly close in cosmic terms. The planet was discovered when astronomers picked up on a slight wobble in the star orbital motion. The back and forth movement of the star is caused by the gravitational pull of the planet upon the star as it moves along its orbit.
“Our observations extended over more than four years using the HARPS instrument and have revealed a tiny, but real, signal from a planet orbiting Alpha Centauri B every 3.2 days,” says Xavier Dumusque of the Geneva Observatory. “It’s an extraordinary discovery and it has pushed our technique to the limit!”
The new planet is not another Earth as the zone in which it travels is certain to be too hot to support life. The planet is only 3.75 million miles from Alpha Centauri B which is too close to allow for the necessary formation of life sustaining liquid water.