Thursday, April 9, 2015

Kepler 78b: Earth Sized Planet Discovered

Kepler 78b: Earth Sized Planet Discovered: APOD: 2013 November 5 - Kepler 78b: Earth-Sized Planet Discovered


Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

2013 November 5


See Explanation. Clicking on the picture will download the highest resolution version available.
Kepler-78b: Earth-Sized Planet Discovered

Illustration Credit: David A. Aguilar (CfA)
Explanation: Even though Kepler-78b is only slightly larger than the Earth, it should not exist. Its size is extraordinary only in the sense that it is the most similar in size to the Earth of any exoplanet yet directly discovered. Its orbit, however, is extraordinary in the sense that it circles a Sun-like star 40 times closer than planet Mercury. At such a scathing distance, even rock is liquid. Models of planet formation predict that no planet can form in such a close orbit, and models of planet evolution predict that Kepler-78b's orbit should decay -- dooming the planet to eventually merge with its parent star. Illustrated above in comparison with the Earth, Kepler-78b was discovered by eclipse with the Earth-trailing Kepler spacecraft and further monitored for subtle wobbles by the HARPS- North, a spectrograph attached to the 3.6-meter Telescopio Nazionale Galileo in the Canary Islands.