A new study by an international team of astronomers reveals that four Earth-sized planets orbit the nearest sun-like star, tau Ceti, which is about 12 light years away and visible to the naked eye. These planets have masses .
The Keck Observatory telescopes on Maunakea in Hawaii, are the world’s largest optical and infrared telescopes. Keck Observatory's vision is to advance the frontiers of astronomy and share our discoveries with the world.
The Rosetta spacecraft used a wide-angle camera to acquire this image of Comet from a distance of 30 kilometers. The nucleus is deliberately overexposed in order to reveal the faint jets of activity. Photographed on on November released on January