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Full Version: Earth-moon L5 Long-Term Stability
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I understand the basics of Lagrange points - L1 - L3 are unstable, L4 and L5 are stable if the two main bodies differ in mass by over a factor of 25 - but how stable are the Earth-moon L4 and L5 points on a period of millions of years, considering the other bodies in the solar system? Earth doesn't have an asteroid collection like Jupiter in its trojan points.

Second, how stable is the situation if alien space bats pop a Vesta-mass asteroid into the Earth-moon L5 point?
Earth does have at least one Earth/Sun Trojan asteroid, so it's not such a chaotic environment that trojans are forbidden.
https://en.wikipedia.org/wiki/Earth_trojan
I'd guess Earth/Moon Trojans would be stable for a relatively long time, but a large object might suffer a series of collisions in the long term if there were lots of other objects there.
(04-09-2016, 05:23 AM)stevebowers Wrote: [ -> ]Earth does have at least one Earth/Sun Trojan asteroid, so it's not such a chaotic environment that trojans are forbidden.
https://en.wikipedia.org/wiki/Earth_trojan
I'd guess Earth/Moon Trojans would be stable for a relatively long time, but a large object might suffer a series of collisions in the long term if there were lots of other objects there.

What sort of effect could these collisions have?
(09-11-2016, 04:41 PM)SteelySam Wrote: [ -> ]
(04-09-2016, 05:23 AM)stevebowers Wrote: [ -> ]Earth does have at least one Earth/Sun Trojan asteroid, so it's not such a chaotic environment that trojans are forbidden.
https://en.wikipedia.org/wiki/Earth_trojan
I'd guess Earth/Moon Trojans would be stable for a relatively long time, but a large object might suffer a series of collisions in the long term if there were lots of other objects there.

What sort of effect could these collisions have?

This post got hung up in our first post Moderation Queue and overlooked somehow, so...bump.

Todd
The debris of such a collision would mostly remain in the Lagrange point volume, and probably cause a risk in that volume so would need to be cleared up. Orbits around a Lagrange point can be quite large, so the debris could be quite sparse- but if secondary collisions occur then a Kessler Syndrome situation could develop.
https://en.wikipedia.org/wiki/Kessler_syndrome
In the early scenario I expect that scrap collectors would be employed to collect dead satellites and the results of such collisions; later, with the emergence of competent AI, such collisions would be rare unless they are caused with malicious intent.