Everyone has seen pictures of, or if lucky enough, seen planets with rings through a telescope before, but what other objects also have rings? In our solar system, all of the Jovian (or big gas giants) planets have rings, even Jupiter. Usually, leftover material floating through space and debris from impacts are what add material to the rings, but other scenarios can add mass, or even create a whole new ring. Take Jupiter’s moon Io for example. This highly volcanic moon is constantly erupting sulfuric gas into the atmosphere. Some of this gas even escapes the moon’s pull of gravity and when the moon spins, it leaves behind a trail of gas and particles. This moon is actually making a new ring around Jupiter. Another extraordinary example of a ring system is portrayed in an unusual place that few would guess; not a planet but an asteroid!
The asteroid Chariklo is about 150 miles across and has rings that are 2 miles and 4 miles wide. Like many other planets and deep space objects, astronomers gather data when that asteroid is between a star and us. By recording the dimming of light from the star, we could calculate the asteroid’s diameter. The surprising part was that the luminosity of the star began to decline slightly even before the asteroid crossed the horizon. This is how we managed to find the two sets of rings around it. Scientists also think that Chariklo could have a moon, or small meteoroid, revolving around it.
Many people ask the question, “If objects with mass attract each other, then why don’t the dust and rock in ring systems just clump together?” First of all, these particles are usually moving really fast. For example, some of Saturn’s rings move at tens of kilometers per second! This results in explosive crashes and broken pieces. The moons that also orbit the main body are another prevention of “clumping”. If a moon is present next to a ring system, it can attract some of the rock and ice. This might move the rings only a fraction of an inch, but that can cause collision after collision of the particles behind it. Saturn even has a few moons that orbit in between its rings. Also, try to visualize planetary rings as very thin. Saturn’s rings span about 280,000 kilometers in length, but only have a 1-kilometer depth.
These new discoveries highlight a major change in the science of astronomy, exemplified by the discovery of gravitational waves and these ring discoveries, the exquisite accuracy of modern and very innovative, creative instrumentation. Discoveries such as this and Planet 9 also show the vastness of space. Just think about it: we are still making discoveries in our own solar system. One tiny speck in the galaxy which is one tiny speck in the universe.