Ok, ok… it’s not “new” (it’s from a HubbleNews article released in 2005) but since I just came across it myself, it’s new to me! So maybe it’s new to you too. 🙂
The video above was created from images taken by the Hubble Space Telescope, showing distant Neptune (we’re talking four and a half billion km away here!) rotating on its axis, four of its 13 known moons visible in orbit. The images were taken every 4-5 hours between the days of April 25th – 30th, 2005, and were then combined to make a dynamic movie animation. And what a cool animation it is!
With an upper atmosphere composed mostly of methane, Neptune appears cyan blue in visible light. Hubble used visible light for the first set of images and then switched to wavelengths of light more sensitive to methane, revealing more details of its dynamic atmosphere. (A total of 14 different filters were used in the observation to get as much information about Neptune as possible.)
Because of the dimness of the sunlight that reaches Neptune, the long exposures needed to make these observations are able to also pick up light reflected from the planet’s moons. 436-km-wide Proteus appears as the brightest one, with Larissa, Despina and Galatea also making appearances.
Neptune also has faint rings, broken up into arc segments, but those are much too faint and thin to be imaged at this distance.
So maybe it’s not new per se, but since Neptune hasn’t been visited by a spacecraft since the Voyager 2 flyby in 1989 I tend to think of any info on this remote member of our planetary family as something special! It’s a fascinating world, boasting a dynamic (and frigid!) atmosphere with some of the fastest winds in the solar system as well as a varied collection of moons, some of which may very well be captured Kuiper Belt Objects (like the huge backwardly-orbiting Triton with its signature “cantaloupe” terrain.) Sadly, there’s currently no planned missions to visit Neptune again in the near future, so these images from Hubble really are our only window to this far-flung planet.
Credit: NASA, ESA, E. Karkoschka (University of Arizona), H.B. Hammel (Space Science Institute, Boulder, CO), and G. Bacon (STScI)