spacetoday.net: Scientists: Pluto may be warming

Posted: Thu, Oct 10, 2002, 8:48 AM ET (1248 GMT)
Planetary scientists analyzing recent observations of the planet Pluto now believe that the planet may be warming, and not cooling as previously thought. A team of scientists led by Jim Elliot of MIT observed two occultations, where the planet passed in front of a star as seen from the Earth, in July and August. Preliminary analysis of the July data showed that the planet's atmosphere has appeared to cool significantly since the last occultation in 1988. However, the latest data, from an August occultation observed at infrared wavelengths in Hawaii, showed that the surface has warmed slightly — about 2 degrees Celsius — since 1988. Scientists suggest that this may be a thermal lag similar to how the warmest part of the day is in the afternoon, and not at noon, since Pluto has been moving away from the Sun in its elliptical orbit since 1989. Scientists also suggested that Pluto may have geysers of dark material erupting from its surface, similar to Triton.