NASA's Cassini spacecraft shows the innermost D ring of Saturn is hurling dust grains coated in its chemical cocktail into the planet's upper atmosphere, which over long timescales, may change the carbon and oxygen content of the atmosphere
Cassini's Ion and Neutral Mass Spectrometer (INMS) team used the mass spectrometer aboard the probe sampled chemicals at altitudes between Saturn's rings and atmosphere. The device detected methane and carbon dioxide, which were unexpected. The rings were thought to be entirely water. But the innermost rings are fairly polluted with organic material caught up in ice.
According to researchers, the material is coming into Saturn at high speeds because the rings are moving faster than the atmosphere quite a bit. It doesn't just drop in gently. It emanates flying like a satellite re-entering earth. These dust grains move at satellite speed, dumping energy that can detach the atmosphere. They think it may be heating the upper atmosphere, changing its composition.