With the help of the space telescope “Hubble” astronomers have discovered a corona of atomic hydrogen surrounding an icy satellite of Jupiter Europe.
Europe has a thin atmosphere consisting mainly of molecular oxygen, which is formed by sputtering and radiolysis of ice on the surface of Europe, in consequence of the bombardment by ions from the magnetosphere. Although molecular oxygen is the densest component of the atmosphere of Europe, as a result of spray ice produced water and molecular hydrogen, the rate of formation of which is comparable with the rate of formation of molecular oxygen. However, scientists know that only non-condensable molecular oxygen accumulates, forming near-surface atmosphere, while other products of spraying are unable to perform this function: water freezes upon contact with the surface of Europe, and light molecular hydrogen is lost to space.
For a deeper study of the mystical atmosphere of Europe a team of astronomers under the leadership of Laurence Roth (Roth, Lorenz) from the Royal Institute of technology in Stockholm, Sweden, Europe observed in ultraviolet light with the help of Hubble in the period between December 2014 and March 2015, for which Europe has made six transits in front of the disk of Jupiter. Scientists wanted to see the local signals of water vapor in the atmosphere of Europe, but to his surprise found a large cloud of hydrogen surrounding the icy moon of Jupiter.
This new study confirms the value of the hydrogen concentration in the global atmosphere predicted in previous studies.