The mysterious exoplanet TrES-2b is a gas giant the size of Jupiter, but it reflects less than 1% of the light that hits it—making it darker than coal and one of the stranger objects astronomers have yet found, reports Discovery. "TrES-2b is considerably less reflective than black acrylic paint, so it's truly an alien world," said one astronomer.
TrES-2b, located 750 light years from Earth, rotates 30 times closer to its sun than the Earth does, heating its gaseous atmosphere to a balmy 1,800 degrees. But while scientists suspect the atmosphere contains light-absorbing chemicals such as vaporized sodium and potassium or titanium oxide, those are not enough to account for the planet's extreme darkness. "However, it's not completely pitch black," said another researcher. "It's so hot that it emits a faint red glow, much like a burning ember or the coils on an electric stove."