Herschel risolve il mistero dell'acqua su Giove
24 Aprile 2013
This mosaic of WFPC-2 images shows the evolution of the G impact site on Jupiter (the 21 comet fragments of Shoemaker-Levy 9 were each assigned a corresponding letter to identify the impact site; G represents the 7th fragment to strike the planet. It was also the largest impact.).
The images from lower right to upper left show: the impact plume at 07/18/94 07:38 UT (about 5 minutes after the impact); the fresh impact site at 07/18/94 at 09:19 UT (1.5 hours after impact); the impact site after evolution by the winds of Jupiter (left), along with the L impact (right), taken on 07/21/94 at 06:22 UT (3 days after the G impact and 1.3 days after the L impact); and further evolution of the G and L sites due to winds and an additional impact (S) in the G vicinity, taken on 07/23/94 at 08:08 UT (5 days after the G impact).
Over 15 years later, ESA's Herschel space observatory has linked water in Jupiter's upper atmosphere to the impact of comet Shoemaker-Levy 9.
Credits: R. Evans, J. Trauger, H. Hammel and the HST Comet Science Team
Distribution of water in the stratosphere of Jupiter as measured with ESA's Herschel space observatory with the PACS instrument at 66.4 microns. The data have been superimposed over an image of Jupiter taken at visible wavelengths with the NASA/ESA Hubble Space Telescope.
A clear asymmetry is shown in the distribution of water, with more abundant in the southern hemisphere (white/cyan) and far less detected in the northern hemisphere (darker blue shades).
A new study using Herschel finally links Jupiter’s upper atmosphere water to the comet impact of Shoemaker-Levy 9 in 1994, during which 21 comet fragments struck the planet at intermediate southern latitudes.
Credits: Water map: ESA/Herschel/T. Cavalié et al.; Jupiter image: NASA/ESA/Reta Beebe (New Mexico State University)