Neptune’s balmy south pole
By Ron Cowen
The first temperature map of Neptune’s lower atmosphere shows that the planet’s south pole is about 10°C warmer than any other place on the planet. The average temperature of the atmosphere’s lower depths is –200°C. The south pole is warm enough for gaseous methane to rise into the upper atmosphere, says study coauthor Glenn Orton of NASA’s Jet Propulsion Laboratory in Pasadena, Calif.
The escaping methane could explain a long-standing puzzle—the presence of methane in Neptune’s stratosphere.