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Space Junk Tracked
TheToon writes "Remember that "new moon" that turned out to be space junk? NASA has traced the path of it, with an animation. Some close misses on the moon, but it turns out just fine. Junk is on its way now, but might be back in 2040."
Keep in mind though, the L1-L3 Lagrangian points aren't dynamically stable enough to attract things to them and keep them there. Only the L4 and L5 points will do that, where they're then usually called Trojans, 60 degrees ahead of and behind the secondary body. For L1-L3, some kind of station-keeping is needed to make something stay put, after some maneuvers to get it into the right place to begin with.
In a coordinate system that tracks the Earth, the L1 point is where the Earth's gravitational well and the Sun's gravitational well meet in a saddle. L1 is a special place where an object can switch between orbiting the Sun and orbiting the Earth (another possibility is the L2 saddle on the other side of the Earth).
An asteroid cannot park itself there because the saddle shape will cause the asteroid to "fall" one way or the other.
Near the earth-sun Lagrange point one. It changes course for no apperant reason. I geuss that is the beauty of Lagrange points.
It's partly that, but mostly just the fact that the picture is in a rotating reference frame. Anything in Earth's gravity well will more or less be dominated by Earth's gravity and have elliptical-looking orbits, but anything outside will follow strange-looking paths instead of the ellipses we expect.
The big hint for this is that the object is deflected down (on the picture) when travelling left to right, but deflected up when travelling right to left, while in both cases travelling above the lagrange point (so neither being consistently attracted nor deflected).