To study the atmospheres of young planets outside our Solar System, we need not look far. The first brown dwarf science with the newly-commissioned FIRE spectrograph has revealed the presence of rock clouds in the atmosphere of a planetary-mass companion to the nearby Ross 458 system. The presence of these clouds, and the planetary nature of the source, defy prior expectations.
The source in question is Ross 458C, a brown dwarf candidate identified in the UKIDSS survey in early 2010 by two independent studies led by Drs. Rolf-Dieter Scholz and Betrand Goldman. This source, also known as ULAS J130041.72+122114.7, is located 1.7′ (0.028 degrees) southeast of the Ross 458 system, a pair of magnetically active M dwarfs only 11.2 pc (36.5 light-years) from the Sun. The colors and faintness of Ross 458C, and that fact that it co-moves with the Ross 458 system, led both studies to conclude that it was potentially a very cool and very low-mass brown dwarf companion. However, neither study had the necessary spectral data to probe its atmosphere.