Transiting Exoplanet (IMAGE) Center for Astrophysics | Harvard & Smithsonian Caption This artist's conception shows the silhouette of a rocky planet, dubbed HD 219134b, as it passes in front of its star. At 21 light-years away, the planet is the closest outside of our solar system that crosses, or transits, its star -- a bonus for astronomers because transiting planets are easier to study. The planet, which is about 1.6 times the size of Earth, is also the nearest confirmed rocky planet outside our solar system. It orbits a star that is cooler and smaller than our sun, whipping snuggly around it in a mere 3 days. The proximity of the planet to the star means that it would be scorching hot and not habitable. Credit NASA/JPL-Caltech Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.