The rings of Saturn are one of the most stunning sights in our solar system. Now, researchers have shown how the gigantic plumes of ice that erupt from the surface of Saturn’s moon Enceladus give one of the rings, the E ring, its distinctive structure.
See that tiny dot on the right? That's Enceladus. Image: NASA/JPL/Space Science Institute
Researchers have known since 1981 that the E ring was created by kilometre-high plumes of ice and water vapour erupting above hotspots on the icy-bound surface of Enceladus. The new study shows that the eight identified plumes on Enceladus contribute to thicker bands of particles within the vertical structure of the ring, and that some plumes are better at doing so than others.
However, even after the particles are blasted free from the moon they end up back there, trapped by the moon’s gravity often after only one or two orbits.
To make their discovery the researchers instructed the Cassini spacecraft currently in orbit around Saturn to dive through the E ring while analysing the particles it passed. The results revealed the unusual vertical stripes, and feeding the data into a computer model of the E ring and Enceladus showed how the plumes create the stripes.
The researchers also show that many of the particles thrown up by the plumes escape into the rings. The rest, particularly the largest particles, fall back to the moon’s surface if their speed is less than around 207 metres per second, although it does also depend on where on the surface of Enceladus the plume originates.
The results of the study could allow researchers to find less obvious plumes by looking closely at the ring structure. They also shed light on the creation of one of the most spectacular features of our corner of the universe.
The ice plumes at the south pole of Enceladus. What goes up... Image: NASA/JPL/Scace Science Institute
Paper Reference: Kempt, S., Beckmann, U. and Schmidt, J. (2010) How the Enceladus dust plume feeds Saturn’s E ring. Icarus, 206 (2), p446-457.doi:10.1016/j.icarus.2009.09.016
Thanks for this post! It’s so interesting.
Hi, thanks for the comment – glad you liked it!