Can someone smart explain to me what this means in leymans terms?

Question

What is a Lagrange point?

Answer 1

Lagrange was a mathematician. He resolved special cases of the "famous" three body problem.

There are five positions where the gravity forces of 2 bodies, on a third, will cause some kind of equilibrium. All five are called Lagrangian points are are labeled L1 to L5. See the link number 1 to see where they are placed.

The SOHO satellite (looking at the sun) is located at Earth's L1. (Between Earth and the Sun) See images from SOHO at link number 2.

L1, L2 and L3 are 'unstable' equilibrium points: an object placed there will stay as long as it is not disrupted. As soon as it is, the effect moving it away will increase. A bit like holding a baseball bat in equilibrium over one finger: if it tilts too much, it will fall. However, as long as you keep your finger moving in the proper fashion, you can keep that stick up there for a long time with little effort.

L4 and L5 are more stable. Any object placed there will tend to stay there. Any small perturbation that tries to move the object away will be overcome by the combined gravity of the Sun and the planet. It is a bit like holding the bat downward (hanging from your hand): if someone tries to tilt it up, it will simply fall back into its equilibrium position under your hand. Of course, if the other person knocks hard enough on it, then the bat may slip out of your hand. Same thing for asteroids.

There are two groups of asteroids on Jupiter's orbit, one group 60 degrees ahead, the other 60 degrees behind, called Trojans (actually, one group is now called the Greeks). So that Lagrangian positions L4 and L5 are sometimes called Trojan positions (whatever the planet being considered). However, the term Trojan asteroids should only be used for the ones in Jupiter's L4 and L5 positions.

The position L3 is on the other side of the Sun. For Jupiter, the satellites that are there are called the Hildas.
See link number 3.

Around Saturn, there are even "Trojan moons" 60 degrees from another moon, on the same orbit.

Answer 2

A LaGrange point is a point in a three-body gravitation system at which the smallest body can be stationary relative to the other two (think of a communications satellite in a geosynchronous orbit around Earth, also held in place by the gravity of the moon) At some point, the gravitational pull of the two larger bodies balance out so that the smallest body can remain at that point if it isn't acted upon by another outside force.

Answer 3

A point of gravitational stability in a three-body system.

Answer 4

Does this help?

http://www.ottisoft.com/samplact/Lagrange%20point%20L1.htm

http://en.wikipedia.org/wiki/Lagrangian_point