Does a planet have to have a relatively large monn for it to have Lagrange points?

Question

Specifically, I'm curious whether Venus has an L1 point?

Answer 1

If the moon is too large ( bigger than 1/25th the size of the planet) then the triangular Lagrange points, L4 and L5, are unstable.

For any object in our solar system, the idea of a Lagrange orbit is an approximation because there are many more than 3 bodies in the solar system, and the Langrange solution is, formally, a solution for three bodies where the two large bodies are in a circular orbit.

Answer 2

Venus does have an L1 point.  All of the LaGrange Points can be defined in terms of the planet and the Sun.

L1 is the point between the planet and the Sun where the gravitational effects of each are balanced just right so that an object in orbit around the Sun has the same orbital period as the planet--even though the object in orbit is -closer- to the Sun than the planet.  No satellite required.

However, one can also have LaGrange points *relative to a satellite*.

A solar L1 point is between the Earth and the Sun.  A *lunar* L1 point would be between the Moon and Earth--and the object in orbit there would orbit the Earth with exactly the same orbital period as the Moon.

So a satellite is not required to have LaGrange Points--they're defined by the bodies for which you choose to calculate them.  But you have -more- LaGrange points if you have a satellite.

Answer 3

All the planets have LaGrange points. It depends on what bodies are you looking to balance out. The earth-moon system has five L-points. Venus-sun has several ( I don't know the exact number) L-points. And Venus has five L-points for a moon, but at present time there is no moon there.

As far as how big the moon needs to be, there is no restriction. The Jupiter-sun system has two L-points which are occupied by the Trojan asteroids and they are just over-sized rocks.

Answer 4

Yes. The L1 point of Venus has been suggested for many fiction and non-fiction projects.