NASA’s Cassini mission spotted a strange signal coming from Saturn’s second-largest moon Rhea – it may be from hydrazine, a compound often used in rocket fuel
Source:
https://www.newscientist.com/article/2265635-puzzling-signal-on-saturns-moon-rhea-may-finally-be-explained/?utm_campaign=RSS%7CNSNS&utm_source=NSNS&utm_medium=RSS&utm_content=home