The images that the space probe Cassini sent of Saturn are so impressive and beautiful that one could almost be jealous of the rings of the great gas planet. It is noticeable that all planets in the solar system that have pronounced or weak rings are gas planets, whether it is the two gas giants Saturn and Jupiter, or the ice giants Uranus and Neptune. Rings represent something ordinary on gas planets. But there is nothing against rings, even with earth-like planets. The only question that arises is where the particles that make up the rings could come from.
It is mainly ice chunks and dust particles that form the rings of the gas planets. Researchers suspect that these are the remains of small ice moons. How do these residues come about? There are different possibilities.
Tidal Forces, Meteorites, Ice Volcanoes – Makes Saturn Rings
It could be, for example, that the small moons once orbited very closely around their planet and ended up getting so close to it that they were torn apart by the tidal forces. Because on the front and back of the moon, the planet attacks with different degrees of attraction. And when a small moon slowly wanders towards the planet, the point will be reached at some point where it can no longer withstand these forces.
In scientific jargon, the moon then crossed the Roche limit. The many small parts into which it is broken down, as a result, can form a comparatively massive ring. So this is a possible source of Saturn rings particles but by no means the only one.
Dust is also created when centimeter-sized meteorites hit the moons. And that happens all the time. All planetary bodies are subject to constant bombardment by micrometeorites for a long time. If dust particles then get into the environment as a result of these impacts, small moons themselves do not have enough gravity to hold these dust particles. The dust particles either immediately go into orbit around the planet or escape into space. The particles remaining on the planet then form thin rings. This is mainly how Jupiter comes to his rings.
The moons that provide the necessary dust. The outermost ring of Saturn feeds itself from a completely different source. Ice volcanoes on the moon Enceladus play the central role here.
The Cassini space probe took sensational photos of eruptions in its south pole region. Ice and dust particles are emitted, which Enceladus, however, with its diameter of 500 kilometers, cannot bind to itself. Its attraction is too weak. A large part of the particles, therefore, go into orbits around Saturn. According to the scientist, there are also particles from volcanic activity in the rings of Jupiter. There it is the Galilean moon Io that contributes to this.
Does Earth Have Rings?
Tidal forces, meteorite bombardment, ice volcanoes, the primordial and original formation of rings remain. This means that the ring system could have been created together with the planet. Then the rings would have been around for almost 4.6 billion years. However, it is unclear whether ring systems can remain stable over such a long period.
Due to frictional forces, the ring particles drift very gradually in the direction of the central planet. This is why the lifespan of ring systems is limited to a much shorter period. They are very likely a dynamic phenomenon and are subject to change.
Now that we have clarified how rings can form, let’s come back to earth. Wouldn’t one or the other of these ring particle sources also be an option for Earth? No, as among the terrestrial planets of the solar system, rings would be conceivable only at Mars.
The small Martian moons Phobos and Deimos are under attack from meteorites, which could very well form thin rings around the red planet. The search for it has so far been unsuccessful but in the distant future, there is still another possibility for Mars to get hold of rings. It is becoming apparent that Phobos, the inner one of the two Martian moons, will cross the Roche limit and break apart around 10 to 20 million years from now.
And in the end, the earth does not go away empty-handed when it comes to rings. If you look into the past and the history of our own moon, you come to a fascinating conclusion – our home planet probably once had a ring. Researchers assume that the earth was hit by a Mars-sized body around 4.45 billion years ago, which evaporated large parts of the fresh earth’s crust and the still-glowing mantle.
This fiery mixture of super-hot rock gases condensed in a huge ring that surrounded the equator of the earth. And what happened to this ring material is particularly exciting as it formed into a new body called the moon.