The VIRTIS instrument detected nightglow emission suggesting the existence of hydroxyl radicals in the upper portion of this entity. In this entity, oxygen is excited into a stable singlet state which relaxes and emits a 1.27 micrometer line. S-shaped bodies connect the two centers of rotation of each of the two polar vortices located here. A 1761 transit observed by Mikhail Lomonosov led him to hypothesize this entity. Ultraviolet radiation possibly caused accelerated (*) oxidation in the upper portion of this entity in the 1970s due to an eruption. Because there's no intrinsic magnetic field, a chunk of this entity is lost to solar wind. Convection drives all winds in this entity, which has a pressure of 93 bar and contains 97% carbon dioxide. The runaway greenhouse effect is thought to 
The VIRTIS instrument detected nightglow emission suggesting the existence of hydroxyl radicals in the upper portion of this entity. In this entity, oxygen is excited into a stable singlet state which relaxes and emits a 1.27 micrometer line. S-shaped bodies connect the two centers of rotation of each of the two polar vortices located here. A 1761 transit observed by Mikhail Lomonosov led him to hypothesize this entity. Ultraviolet radiation possibly caused accelerated (*) oxidation in the upper portion of this entity in the 1970s due to an eruption. Because there's no intrinsic magnetic field, a chunk of this entity is lost to solar wind. Convection drives all winds in this entity, which has a pressure of 93 bar and contains 97% carbon dioxide. The runaway greenhouse effect is thought to be responsible for the current state of this entity. Opaque clouds of sulfuric acid are present in, for 10 points, what entity that prevents the surface of the second planet from being seen by visible light?
The VIRTIS instrument detected nightglow emission suggesting the existence of hydroxyl radicals in the upper portion of this entity.