IO ELECTROLYTIC SNOW.

IO is far far more awesome than the poorly informed suspect, and the best informed know. It's just shooting out copious ions into the Jovian environment via regular volcanic eruptions that can be ten percent of the planets area. The Flux Tube and Plasma Torus are potential energy sources that with current tech could potentially power a permanent satellite, or more. 

The ions that IO is pumping are strong ones, mostly oxygen and sulfur in the form of SO2. However this IMRAD is looking for other combinations, such as S2O and other poly-sulfur oxides, because again, Oxygen and Sulfur are very reactive, and will do something with any molecule, especially ions, that they meet in Jupiter's extreme environment. 

In the introduction the plan is to match color, spectroscopy and where these things show up on IO's map. Non-SO2 molecules should appear in redder spots.

In the methodology section the team specifies using the Hubble's spectrograph to take 8 samples of spectroscopy mixed with some Galileo data. To pull facts out of the data a deep knowledge of spectroscopy is needed, so there is a whole definitions section with subsections to help folk who want to recreate or interrogate the results. You don't have to read any of it if you don't want to.

The results start in section 4.1. Unsurprisingly a lot of equatorial SO2. SO2 will freeze straight out of the void at these locations, producing a frost or less likely, a snow. The results are somewhat inconclusive, which was expected, but it looks like they found among other things, Red-Sulfur-Glass, Na2S, S2O and maybe iron ions. The red sulfur glass in particular is a fun idea. This morphology of sulfur seems to be unique to IO. This S4 ice-glass seems to be part of all the reddest areas on the surface of IO.

At the end the team really does not stick their necks out too much, just speculating about the sulfur glass. The papers expressed purpose was to explore a spectroscopy range that had not been looked at yet, and to that end it was fully successful. However the exploration did not really conflict with Voyager or Galileo data so much as reinforce it, so the conservative conclusions are a good thing.