The Rings of Jupiter

A side view of Jupiter's Rings from Galileo spacecraft

Image Credit:

NASA, JPL, Galileo Project, (NOAO), J. Burns (Cornell) et al.



Saturn is not the only planet with rings. All the Jovian planets have some sort of ring system, though Saturn's rings are the most impressive. Jupiter's rings are so thinly distributed that they were not discovered until 1979 when Voyage I discovered them on its journey through the Solar System.

Jupiter's rings are not as bright as Saturn's rings, which are mostly composed of ice compounds. Jupiter's rings are dark and reddish which tells us that the material making up the rings are of a rocky origin. The ring is located within the Roche limit, the distance from Jupiter where gravity would rip apart a poorly consolidated moon, asteroid, or comet wandering inside that distance. The origin of the ring is probably a moon or asteroid that wandered too close to Jupiter.

 

The rings of Jupiter would have been dissipated long ago if the ring was not continuously replenished by the moons near the rings. The moons get hit by small meteorites, impacting the surface of the moon, and blowing dust out into orbit. This dust then gets incorporated into the rings. We know this by looking at the distribution of dust particles in the rings and see that the portions of the rings near moons are more densely packed with dust than those sections farther away. For example, near the moons Amalthea and Metis, the ring is densest between these moons. Amalthea orbits just outside the ring and Metis, just within the rings diameter.

 

Besides the main ring seen above, there is a much thinner ring outside Amalthea's orbit. This ring is called the gossamer ring because it is so thin. Again, by noting that this ring is densest near Amalthea and Thebe (orbiting farther out from Amalthea), we can conclude that micrometeorite impacts keep the rings intact. Also, Amalthea, Metis, and Thebe are also shepherd satellites of the rings, which will be explain more in detail when we talk about Saturn, its rings, and its moons.