Saturn’s moon Dione is spotted with long brilliant stripes, and nobody understands how they arrived.

Planetary researchers initially discovered the stripes in photos taken with NASA’s Cassini spacecraft, which orbited Saturn from 2004 to 2017 ( SN: 4/14/18, p. 6). Discovered near the moon’s equator, the long, thin, brilliant lines run remarkably parallel to each other for 10s to numerous kilometers. And the stripes appear untouched by other functions in the pocked and ridge-lined landscape, scientists report online October 15 in Geophysical Research Study Letters

” They’re simply truly strange,” state research study coauthor and planetary researcher Emily Martin of the Smithsonian National Air and Area Museum in Washington, D.C. “It’s truly amazing when you see something truly odd, and you’re simply attempting to determine what the heck it might perhaps be.”

Dione’s distinct marks aren’t the only streaks in the planetary system. So Martin and planetary researcher Alex Patthoff mapped the structures and compared them with straight lines discovered on other heavenly bodies, consisting of the Saturnian moon Enceladus, Earth’s moon and Jupiter’s moons Ganymede and Callisto to see if any of them might provide ideas to the mystical stripes.



The most well-known stripes in the Saturn system are on icy moon Enceladus, which gushes plumes of water from “tiger stripes” near the moon’s South Pole. Those stripes are believed to be fractures in the moon’s icy crust that open and close with gravitational presses and pulls from Saturn and other moons, consisting of Dione.

Nevertheless, the tiger stripes are not as straight as Dione’s streaks, with kinks and twists that follow the underlying surface.

” These things on Dione, you can actually take a ruler and line it up,” states Patthoff, of the Planetary Science Institute based in La Habra Heights, Calif. “We have actually never ever seen anything this straight and this direct anywhere, even in the world.”

Earth’s moon

Earth's moon

Our own moon sports long, direct grooves sculpted by rolling stones. Those stripes are generally less than 10 kilometers long and have a clearly scalloped shape. They likewise, obviously, constantly run downslope.

Dione’s stripes need to be triggered by something else, Martin and Patthoff state, given that they’re a lot longer, do not appear to follow hills and are extremely consistent in width throughout their entire lengths.

Ganymede and Callisto

Ganymede (left) and Callisto (right)

Jupiter’s moons Ganymede (above left) and Callisto (above right) have lines of pits or craters set up in oddly straight rows, which planetary researchers call catena. They’re believed to form from a ripped-up comet. When a comet comes too near to Jupiter, the huge world’s gravity can shred the comet into a stream of rocky particles. When Ganymede or Callisto’s orbits take them past the cometary remains, the particles can smack into the moons in a straight line.

However that’s not a great suitable for Dione’s stripes, either– like the moon’s stone tracks, catena are too brief and scalloped.

So what’s happening with Dione?

ring rain “( SN Online: 10/ 4/ 18 ). Or the stripes might originate from micrometeorite effects kicking product off of 2 other moons that share Dione’s orbit, Helene and Polydeuces. (***** ).

Depending Upon where the infalling product originated from, the lines” might be indicating an occasion in the Saturn system that we had not formerly learnt about,” Martin states.