Europe, the fourth moon of Jupiter
The hot gas around the fourth moon of Jupiter shows plumes and signals of particular activities. Researchers disprove theories developed in the past and say that the thin gaseous envelope contains only single atoms of oxygen and molecular oxygen.
News from Europe, the fourth moon of the planet Jupiter. A group of researchers has recently analyzed data obtained in 2001 by the Ultraviolet Imaging Spectrograph (UVIS), mounted on the spacecraft NASA / ESA / ASI Cassini, to determine the state of the gas in the atmosphere of Jupiter’s satellite.
The results show that the thin atmosphere of Europe should little to the process of introduction of the gas produced by the geology of the satellite. If indeed, this dynamic activity is too low to be detected by the probe, said Amanda Hendrix (researcher at the Planetary Science Institute in Los Angeles and co-author of the study). “And of course possible – even likely – it can occur to some activity, but it is sporadic and the peaks are more basic than those observed on Enceladus. If the eruptive activity had been ongoing at the time of the Cassini flyby, it would be at a level too low to be detectable by UVIS”, reiterates Hendrix.
Using data collected UVIS, the research team led by Don Shemansky, the author of the paper, saw that most of the gas around Europe does not come from the moon itself, but from volcanoes on the moon Io nearby. In fact, from their data the researchers calculated that the atmosphere of Europe contributes 40 times less than previously thought to the contribution of oxygen to his surroundings. And this is a fact to be reckoned with as the natural satellite of Jupiter, and one of the largest of the Solar System, is considered as a place where they could be found traces of microbial life (hypothetically) given the presence of a immense ocean beneath its crust.
Europa, Earth, Moon – Comparison
“Our work shows that researchers have overestimated the density of the atmosphere of Europe,” said Shemansky. The team found that the atmosphere of the moon, in the past already believed to be millions of times thinner than Earth’s, is actually about 100 times less dense than previous estimates. The data also reverses a number of other theories developed in the past believed that the atmosphere of Europe, composed for the most part by molecular oxygen (O2): what has been recently discovered, however, is that the thin gaseous envelope contains only individual atoms of oxygen. Experts in the past have brought forward the theory about a phenomenon called sputtering. This is when charged particles collide with the ice water on the surface of Europe free oxygen atoms that are joined to the atmosphere. The authors of the latest study on Europe, however, believe that a process even more energy to break molecular oxygen: the ions are loaded from the super-fast rotation of the magnetosphere of Jupiter and when they collide with the surface of Europe sent a powerful shock electricity to the ice water molecules breaking the bonds that hold them together.
One step forward, then, in the solution of the mystery of Europe and its atmosphere: on its surface are clear and obvious signs of recent activity, but in fact data from the Cassini spacecraft say anything. The future European and US probes will provide us with more clues to learn about the moon of Jupiter.