Researchers created this enhanced-color image by compositing recent shots of Tethys taken by Cassini. Current top hypotheses for the unusual red arcs are:
1. Banksy
2. Chairface
3. Scraped by another planet in the grocery store parking lot
4. Exposed ice with chemical impurities
5. Outgassing
6. Fractures that are below the resolution of the available images
7. Aliens
Until we hear otherwise, #7 seems most likely.
• Unusual Red Arcs Spotted on Icy Saturn Moon (Jet Propulsion Laboratory)