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« on: June 09, 2017, 05:33:57 PM »
A little bit more clarification, 'gravity wells' are just any object with mass. A singularity is an 'infinitely deep' gravity well. Lagrangian points are not gravity wells, they are points where the gravitational forces of the two objects balance out. The easiest place to see this is at L1 where the forces from the two bodies are equal and opposite creating zero net force. At the other Lagrangian points, the physics are a little more complicated, the forces don't balance to zero, but the resultant of the two forces is exactly strong enough and in the right direction so that an object can stay in orbit at that point without any outside forces (as many people have pointed out, the point remains fixed relative to the two bodies). Any two bodies orbiting one another have Lagrangian points.
Another little bit of information, L4 and L5 are stable points meaning if you move a little away from them, you will be pulled back into them. This means they tend to 'capture' asteroids. L1, L2 and L3 however are unstable meaning if you move a little away from them, you will 'fall away' from them. Again, this is easiest to picture at L1, if you move a little towards the sun, the gravitational force of the sun will increase and you will get pulled into the sun. It makes sense that there is stuff trapped at L4 and L5 but not the other points.