In the News this month: and finally, seasons on Pluto
This is the most detailed view to date of the entire surface of the dwarf planet Pluto, as constructed from multiple NASA Hubble Space Telescope photographs taken from 2002 to 2003. The center disk (180 degrees) has a mysterious bright spot that is unusually rich in carbon monoxide frost. CREDIT: NASA, ESA, and M. Buie (Southwest Research Institute)
On February 4th, new images of Pluto were released showing a surprisingly dynamic surface. Actually taken in 2002 and 2003, the new images from the Hubble Space Telescope aren't sharp enough to pick out individual surface features, even Hubble lacks the resolution to image Pluto in that amount of detail, but they do reveal a varied surface with patches that have changed in brightness considerably since the previous set of images taken in 1994. The images suggest that Pluto's surface and atmosphere undergo dramatic seasonal variations. In the nine years since the previous images were taken, Pluto has become significantly redder and the northern hemisphere has increased in brightness. The changes in surface brightness are likely caused by the seasonal effects of surface ice sublimating at one pole and refreezing on the other as Pluto moves in its 248-year orbit around the Sun. Observations like this will be used to plan the images taken by the New Horizons probe as it flies past Pluto at high speed in 2015.
This blog post is a news story from the Jodcast, aired in the March 2010 edition.