3w ago

A Tiny Moon Creating Giant Waves in Saturn’s Rings

Daphnis, a small moon of Saturn, orbits within the Keeler Gap and exerts a noticeable gravitational pull on Saturn’s rings. This effect creates striking wave-like patterns along the ring edges, offering a visual glimpse into gravitational interactions in planetary systems.

Source: NASA : https://science.nasa.gov/saturn/moons/daphnis/

13 comments

Is this a real "photograph" (including non-visible or even radar imagery) or computer generated from a simulation of some sort?
- This is almost certainly an exaggerated rendering, however this is an actual photo from 2017:
  Source
  There's a few different photos in different articles, but I haven't found the image in the OP anywhere. The OP image is straight from reddit.
  Edit: This one is my favourite:
  Also:
  The waves Daphnis causes cast shadows on Saturn during its equinox when the sun is in line with the plane of the rings.
  Edit2: Here's another that shows the ripples ahead and behind the moon. This happens because the inner ring orbits faster than Daphnis, while the outer ring orbits slower:
  Here's a Daily Mail article that looks like the OP. Apparently this was from a simulation released by NASA in 2016. So basically they were superseded by actual images from Cressini's subsequent passes in 2017.
  
  Thanks for that handy search result link.
  Really makes me want to play Rings of Saturn again :)
- Here's one taken from visable light:
  https://commons.m.wikimedia.org/wiki/File:Daphnis_edge_wave_shadows.jpg#mw-jump-to-license
  (Sorry i haven't figured out how put an image i to a comment on piefed yet)
  Daphnis, 8 kilometers (5 miles) across, occupies an inclined orbit within the 42-kilometer (26-mile) wide Keeler Gap in Saturn's outer A ring.
  Measurements of the shadows in this and other images indicate that the vertical structures range between one-half to 1.5 kilometers tall (about one-third to one mile), making them as much as 150 times as high as the ring is thick. The main A, B and C rings are only about 10 meters (about 30 feet) thick. Daphnis itself can be seen casting a shadow onto the nearby ring.
  This image of shadows on the rings and others like it (see PIA11656 and PIA11655) are only possible around the time of Saturn's equinox which occurs every half-Saturn-year (equivalent to about 15 Earth years).
  
  What an incredible image.
  I almost like it more than the artist rendition, even though it is way easier to understand/visualize.
  
  This image of shadows on the rings and others like it (see PIA11656 and PIA11655) are only possible around the time of Saturn's equinox which occurs every half-Saturn-year (equivalent to about 15 Earth years). The illumination geometry that accompanies equinox lowers the sun's angle to the ringplane and causes out-of-plane structures to cast long shadows across the rings.
  Super cool to read about this. Thanks for sharing
- Artist’s rendition. The original photo is still quite impressive though.
Is the outer ring spinning in the opposite direction or something?
- Spinning the same direction but the angular velocity is higher for lower orbits so the moon orbits faster than the outer ring.

13 comments