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Ios atmosphere is predominately SO2 sustained by a combination of volcanic outgassing and sublimation. The loss from the atmosphere is the main mass source for Jupiters large magnetosphere. Previous studies attributed various transient phenomena in Ios environment and Jupiters magnetosphere to a sudden change in the mass loss from the atmosphere supposedly triggered by a change in volcanic activity. Since the gas in volcanic plumes does not escape directly, such causal correlation would require a transient volcano-induced change in atmospheric abundance, which has never been observed so far. Here we report four observations of atmospheric SO2 and NaCl obtained with the IRAM NOEMA interferometer. These observations are compared to measurements of volcanic hot spots and Ios neutral and plasma environment. We find a stable NaCl column density in Ios atmosphere. The SO2 column density derived for December 2016 is about 30% lower compared to the period of March to April 2017. This increase in SO2 from December 2016 to March 2017 might be related to increasing volcanic activity observed at several sites in spring 2017, but the stability of the volcanic trace gas NaCl and resulting decrease in NaCl/SO2 ratio do not support this interpretation. Observed dimmings in both the sulfur ion torus and Na neutral cloud suggest rather a decrease in mass loading in the period of increasing SO2 abundance. The dimming Na brightness and stable atmospheric NaCl furthermore dispute an earlier suggested positive correlation of the sodium cloud and the hot spot activity at Loki Patara, which considerably increased in this period. The environment of Io overall appears to be in a quiescent state, preventing further conclusions. Only Jupiters aurora morphology underwent several short-term changes, which are apparently unrelated to Ios quiescent environment or the relatively stable atmosphere.
We report on high-resolution and spatially-resolved spectra of Io in the 4.0 {mu}m region, recorded with the VLT/CRIRES instrument in 2008 and 2010, which provide the first detection of the { u}1 + { u}3 band of SO2 in Ios atmosphere. Data are analyz
The search for life beyond the Solar System is a major activity in exoplanet science. However, even if an Earth-like planet were to be found, it is unlikely to be at a similar stage of evolution as the modern Earth. It is therefore of interest to inv
11 transient bright flashes were detected in Jupiters atmosphere using the UVS instrument on the Juno spacecraft. These bright flashes are only observed in a single spin of the spacecraft and their brightness decays exponentially with time, with a du
Early in the Moons history volcanic outgassing may have produced a periodic millibar level atmosphere (Needham and Kring, 2017). We examined the relevant atmospheric escape processes and lifetime of such an atmosphere. Thermal escape rates were calcu
When comet nuclei approach the Sun, the increasing energy flux through the surface layers leads to sublimation of the underlying ices and subsequent outgassing that promotes the observed emission of gas and dust. The ejection of dust requires that th