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Ah ok first point makes perfect sense. How do we know we had rings around earth for so long? And where did they go?
by missedthecue 4y ago
Ah ok first point makes perfect sense.
How do we know we had rings around earth for so long? And where did they go?
- vvilliamperez 4y agoRings of space debris coalesce into small celestial bodies over time. That's one theory of how moons form.
- Nux 4y agoGravity had them I guess. Saturn's going to lose the rings as well, and "soon" (hundreds or thousands of years).
- balfirevic 4y agoDid you mean hundreds or thounsands of millions of years?
- moffkalast 4y agoAbout 100-300 million years, and they only formed sometime in the last 100 million. A blink of an eye from a cosmic standpoint. For comparison, the dinosaurs existed before than the rings did.
- petrocrat 4y agodid a large collision during the era of the dinosaurs also form Saturn's rings then? If so what residual evidence of that collision do we know about?
- Nux 4y agoYes, my bad
- causi 4y agoThe short answer is "math". The material either coalesced into the moon or eventually fell back to earth. It's actually a pretty short lifetime for the rings, compared to ring systems like Saturn. Earth has several disadvantages when it comes to maintaining a set of rings. It doesn't have gravity strong enough for tidal forces to tear orbiting bodies apart at far remove from the planet and it doesn't have "shepherd moons" to keep ring material in a stable orbit.
- verisimi 4y agoCould maths be used to prove the exact opposite, to show why the earth still has rings? I know it doesn't, but I say you can use maths to prove whatever you like. So, 'maths' as an answer, is not satisfactory to me. AFAIK, all this discussion is in the realms of hypothesis.
- toiletfuneral 4y ago
- causi 4y agoAFAIK, all this discussion is in the realms of hypothesis. It is. It's just currently the best hypothesis, and it's refined to better match observation over time. For example, the impact with Theia was originally thought to be a glancing blow by a planet spinning similarly to earth, but more recent simulations indicate it was a head-on collision and that Theia had relatively little angular momentum. This hypothesis does make predictions about the moon's core that are falsifiable but it may be some time before we figure out a way to make the necessary measurements.
- pungentcomment 4y agoSaying it' maths is simplifying it a bit. They use simulations. They can simulate how an object orbits and eventually fall down to earth. They can test those simulations everyday by predicting where a know object in orbit will be in the future. Multiply that by a billion and you can predict that earth's rings would have fall down eventually.
- 4y ago
- ru552 4y agoThe earth is littered with moon rocks. Said rocks may have formed the rings that have dissipated.
- Tagbert 4y agoThose rocks identifiable as moon rocks on the surface of the earth are from ejected debris from the later meteor collisions that formed the craters that we can see on the moon. The early collision debris would have fallen on the molten surface of the earth and been absorbed.
- bmurphy1976 4y agoSaturn also has conveniently placed moons that help keep the rings locked in place.