Astronomers detect hydrogen corona of Jupiter's moon Europa January 30, 2017 by Tomasz Nowakowski report Please Register or Log in to view the hidden image! Jupiter's icy moon Europa. Credit: NASA/JPL-Caltech/SETI Institute (Phys.org)—Using the Hubble Space Telescope (HST), astronomers have spotted an atomic hydrogen corona around Jupiter's icy moon Europa. The discovery which could improve our understanding of Europa's tenuous atmosphere was published Jan. 13 in the Astronomical Journal. Read more at: https://phys.org/news/2017-01-astronomers-hydrogen-corona-jupiter-moon.html#jCp excerpt: The new research confirms the abundance of hydrogen in Europa's global atmosphere that was predicted in previous studies. In particular, the scientist's analyzed the images constraining atmospheric absorption of Jupiter's Lyman-alpha dayglow above the limb of Europa during the transit. They managed to constrain the abundances of atomic hydrogen in the moon's extended corona and derive upper limits for local water vapor abundances from plume activity. "The amount of hydrogen we observed was actually expected to exist and ultimately originates from the erosion of Europa water ice surface," Lorenz said. Read more at: https://phys.org/news/2017-01-astronomers-hydrogen-corona-jupiter-moon.html#jCp
Not decrying the incredible "New Horizons" mission and Pluto, but I do remember being bitterly disappointed when an Europa mission, was put on the back burner in favour of the Pluto/Charon/New Horizons mission. Great research and data obviously from that mission, but I still get a tinge of regret that any Europa mission was discarded for the time being.
