Think about the planets in the Solar System; Saturn has rings, so do Jupiter, Uranus and Neptune. So what about Mercury? Does planet Mercury have rings?
Sorry, Mercury doesn’t have rings right now. I say right now, because it’s possible that Mercury has had rings in the past, and it could have them again in the future.
There are two ways that scientists think a planet can get rings. The first is the icy rings around Saturn, Jupiter, Uranus and Neptune. Scientists think that Saturn’s rings come from an icy object or moon that was crushed under Saturn’s gravity, becoming its rings. It’s also possible that the ring material just formed in place back when the Solar System formed. We also know that some of Saturn’s moons, like Enceladus, are continuing to spew fresh material into the rings.
Unfortunately, Mercury could never get rings like this. That’s because it’s too close to the Sun. The powerful solar winds blast out from the Sun, and would melt and destroy any icy rings around Mercury. In fact, ice can’t exist closer to the Sun than the asteroid belt, unless it’s hidden in shadow, or protected by an atmosphere like we have on Earth.
The second way for a ring to form is for an asteroid or moon to get too close to a planet and be torn apart by gravity. For a few million years this crushed asteroid would appear as a ring around Mercury, until the chunks finally fell down onto the planet. Astronomers predict that the Martian moon Phobos will eventually suffer this fate, be torn apart by Mars’ gravity, and form a ring for a while.
Mercury doesn’t have any moons, and there aren’t many asteroids that might interact with it, so it might never get a ring – but maybe one day. One thing’s for sure, though, there are no Mercury rings today.
How many rings does Mercury have? Zero.
We have written many stories about rings here on Universe Today. Here’s an article about the Martian moon Phobos might only have 10 million years to live, and here’s an article about what Saturn’s rings are made of.
We have also recorded a whole episode of Astronomy Cast that’s just about planet Mercury. Listen to it here, Episode 49: Mercury.
NASA Science for Kids