Hubble detects traces of water in the atmosphere of one of Jupiter’s moons

Orbiting observatory Hubble has for the first time recorded traces of water vapor in the atmosphere of Ganymede, one of the largest moons of Jupiter. Opening, which writes edition Nature Astronomy, will help scientists understand the history of the formation of the gas envelope of Ganymede.

As the authors of the new study, it is believed that the thinned atmosphere of Ganymede was formed by the process of evaporation of ice from the surface of the satellite under the influence of solar radiation. However, until now, it was not possible to detect water in the atmosphere of Ganymede. Now, thanks to the Hubble telescope, the situation has changed.

Astronomers managed to detect traces of water in the gas shell of Jupiter’s moon, whose group was headed by Kurt Rutherford of the Southwest Research Institute of the United States. The researchers analyzed observations from April 2018, when Ganymede plunged into the shadow of the gas giant for several hours.

By comparing the data with earlier observations, the scientists were able to “remove” the oxygen trace from the spectrum of Jupiter’s moon, resulting in the discovery of “water” lines in Ganymede’s spectrum. Before that, they were suppressed by a stronger signal of oxygen ions. The new data allowed scientists to estimate the concentration of water vapor in the gas shell of Ganymede, and found that the index is very different on the bright and dark sides of the moon.