Clouds swirling above the surface of Pluto suggests more climate variation than scientists previously thought. This is based on new images transmitted by the New Horizons spacecraft. These images show a few (around one percent of the atmosphere above the planetoid surface) clouds. The clouds are scattered around the dwarf planet. Until now Pluto was assumed to have clear skies.
The new images show seven apparent clouds within a particular area of the planet. The images, Science News reports, were taken in July 2015, but like many of the readings and images from space probes the data takes a long period of time to be transmitted back and then scientists need time to analyse the readings.
The clouds have been detected across images showing how day turns to night. Around this time, several isolated bright patches are evident. The information was discussed at the October 2016 meeting of the American Astronomical Society’s Division for Planetary Sciences, from a presentation given by Alan Stern who led the New Horizons mission.
New Horizons is an interplanetary space probe that was launched as a part of NASA’s New Frontiers program in 2006. The main mission of the spacecraft was to perform a flyby study of the Pluto system. Following this the spacecraft went onto study Kuiper belt objects. The Kuiper belt is a circumstellar disc in the Solar System beyond the planets; the region is a type of asteroid belt (much bigger than the one between Mars and Jupiter: 20 times as wide and 20 to 200 times as massive).
The study of Pluto’s clouds remains at an early stage. However, the images are consistent with clouds forming at sunset and sunrise as they might around planet Earth. “If there are clouds, it would mean the weather on Pluto is even more complex than we imagined,” Stern told NASA.
As to what the clouds are formed from, this is ethane, acetylene or hydrogen cyanide, or a combination thereof. This is reasoned from earlier studies of Pluto’s atmosphere. The height of the clouds relative to the planetary surface is uncertain. The unusual clouds tally with another interesting feature about Pluto. The dwarf planet appears to have snowy mountains, but these are not composed of frozen water but instead they are formed of methane.
Such answers will probably only come after the next spacecraft is sent out into the far reaches of our solar system.
