A study published in the Journal of Geophysical Research has for the first time revealed that the atmosphere of Jupiter's volcanic moon, Io, is constantly fluctuating. The study, funded by the National Aeronautics and Space Administration, found that the satellite's thin atmosphere freezes during eclipses every day and converts back to gas when the moon emerges. Eclipse occurs two hours of every Io day (1.7 earth days). It proves that Io's atmosphere is in a constant state of collapse and repair.

Constantine Tsang, a scientist at the Southwest Research Institute in the United States, said, "This research is the first time scientists have observed this remarkable phenomenon directly, improving our understanding of this geologically active moon.” Data showed that Io's atmosphere begins to "deflate" when the temperatures drop from minus 148 degrees Celsius in sunlight to minus 167 degrees Celsius during eclipse.

The study, which was carried out using the eight-metre Gemini North telescope in Hawaii and the Texas Echelon Cross Echelle Spectrograph, also explains that "in full eclipse, the atmosphere effectively collapses, as most of the sulfur dioxide gas settles as frost on the moon's surface. The atmosphere redevelops as the surface warms once the moon returns to full sunlight." Researchers said that TEXES measures the atmosphere using heat radiation while the Gemini telescope can sense the faint heat signature of Io's collapsing atmosphere.

Jupiter's moon is "the most volcanically active object in the solar system." The volcanoes are caused by tidal heating, the result of gravitational forces from Jupiter and other moons. The sulphur dioxide spewed out by its many volcanoes creates the moon's thin atmosphere, reported the Daily Mail.