Max Planck Institute for Solar System Research (MPS) | 2020 May 12
New simulations indicate that Jupiter's fourth largest moon ejects water from its subsurface ocean into space.
A layered inner structure including a liquid iron core, a thin oxygen-rich atmosphere, an induced magnetic field - Jupiter's fourth largest moon, Europa, has greater resemblance with a planet than with a primitive moon. Another special feature: the up to 18-kilometer thick outer crust of frozen water covers a subsurface ocean of water. With the new calculations by a group of researchers led by the European Space Agency (ESA) and MPS, there is now increasing evidence that the Jovian moon releases this water into space, at least occasionally, in cryovolcanic eruptions referred to as plumes. Saturn’s moon Enceladus is known to display similar behavior. During NASA’s Cassini mission, the onboard cameras took spectacular images of its plumes.
Comparable and conclusive proof that also Europa spouts water into space is still missing. "However, various theories, models, and sporadic observations suggest that Europa, too, can exhibit plumes”, says MPS scientist Dr. Elias Roussos. In recent years, researchers from several institutes in Europe and the USA have independently found evidence of a specific plume. Some of these groups evaluated data from the magnetometer on board NASA’s Galileo spacecraft, which from 1995 onwards spent eight years exploring the Jovian system. During a fly-by of Europa in 2000, the measured data showed deviations in Jupiter’s magnetic field near the moon. These could be due to a plume that occurred at the same time. ...
An Active Plume Eruption on Europa During Galileo Flyby E26
as Indicated by Energetic Proton Depletions ~ H. L. F. Huybrighs et al
- Geophysical Research Letters 47(1):087806 (28 May 2020) DOI: 10.1029/2020GL087806