Artist's conception of the newly discovered planet MOA-2007-BLG-192Lb orbiting a brown dwarf "star" with a mass of only 6% of that of the Sun. Theory suggests that the 3-earth-mass planet is made primarily of rock and ice. Observational and theoretical studies of brown dwarfs reveal that they have a magenta color due to absorption by elements such as sodium and potassium in their atmospheres. Credit: NASA's Exoplanet Exploration Program
