NASA-funded researchers say that Jupiter’s volcanic moon Io has a thin atmospheric layer that collapses in the shadow of the planet and becomes ice. They have also revealed the effects of freezing of its shadow on the moon’s volcanic gasses, during the eclipses that occur daily.
While passing behind Jupiter, Io cools down to a temperature of 235°F (-148°C) to -270°F (-168°C), and its atmosphere that mostly consists of sulfur dioxide collapse. Just to inform you, Io is the most volcanically active object in the solar system.
The research also says that this phenomenon lasts for two hours of each Ionian days (equivalent to 1.7 Earth days). The atmospheric sulfur dioxide settles on the surface of the moon as frost. Being a geologically active moon, the appearance of such an event improves the scientists’ chances of properly studying the object. This was confirmed by Constantine Tsang, a scientist at the Southwest Research Institute in Boulder, Colorado.
These volcanoes are caused by tidal heating, resulting from gravitational forces from Jupiter and its other moons.
The resultant geological activity, largely consisting of volcanic eruptions, create umbrella-like clouds of sulfur dioxide gas that can reach up to 480 km above the surface of the moon and produce massive chunks of explosive lava fields that flow up to hundreds of miles.
Study co-author John Spencer said that the atmosphere of the moon is constantly collapsing and repairing that is mostly dominated by the “sublimation of SO2 ice.”
Despite the hyperactive volcanoes being highly responsible for the SO2 supply to the atmosphere, the atmospheric pressure is mostly controlled by the sunlight by directly affecting the temperature of the ice. Spencer also said that this had long been suspected by the scientists, but never had they seen such activity.
The researchers explained that observing the phenomenon directly required high spectral resolution, high time sensitivity, and a good signal-to-noise ratio. This was achieved by combining observations made by the Spectrograph from Texas Echelon Cross Echelle and the Gemini North eight-metre telescope located in Hawaii.
These observations were dated back to two nights in November 2013. During these events, the Io was seen moving into the shadow of Jupiter for about 40 minutes. This could prove to be a frequent activity.
This study was published in the Journal of Geophysical Research and was funded by the Solar System Workings and Solar System Observations program wing of NASA.