Darkest Known Exoplanet: Alien World Is Blacker Than Coal

Patrick F. -- Recent work by astronomers has led to the discovery of the darkest known exoplanet. TrES-2b, a Jupiter sized gas planet, reflects less than one percent of all light. The cause of this level of light reflection is believed to be due to  TrES-2b's unusual lack of ammonia clouds, the feature that gives Jupiter its brighter quality. At only five million kilometers from the planet's star,  TrES-2b's heat is over 1000 degrees Celcius making it far to hot for the formation of ammonia clouds. Despite this unique condition, astronomers are still uncertain what is responsible for making the planet so extraordinarily dark. After more observation, astronomers conclude that  TrES-2b, like Earth's moon, is tidally locked in its orbit and so only has one side continually facing its star. Even more unique, evidence supports an almost negligible level of reflectivity inherent in  TrES-2b's surface, a trait not yet discovered within any known planetary system.

            These discoveries will go a long way in providing conclusive evidence on the variability of planets. Data from planets with a similar, yet less extreme, level of luminescence, will allow astronomers to learn more about the chemical compounds that produce this phenomenon. From there, discoveries may be made about the conditions necessary for such a unique planetary quality to form. To begin this search, the astronomers who discovered  TrES-2b are conducting searches among over 1,200 planetary candidates in search for those with similar qualities as this extraordinarily dark exoplanet.


Link:  Darkest Known Exoplanet