Alien world is blacker than coal
Astronomers have discovered the darkest known exoplanet — a distant, Jupiter-sized gas giant known as TrES-2b. Their measurements show that TrES-2b reflects less than 1 percent of the sunlight falling on it, making it blacker than coal or any planet or moon in our solar system. “TrES-2b is considerably less reflective than black acrylic paint, so it’s truly an alien world,” said astronomer David Kipping of the Harvard-Smithsonian Center for Astrophysics (CfA), lead author on the paper reporting the research. In our solar system, Jupiter is swathed in bright clouds of ammonia that reflect more than a third of the sunlight reaching it. In contrast, TrES-2b (which was discovered in 2006 by the Trans-Atlantic Exoplanet Survey, or TrES) lacks reflective clouds due to its high temperature. TrES-2b orbits its star at a distance of only 3 million miles. The star’s intense light heats TrES-2b to a temperature of more than 1,800 degrees Fahrenheit...