Once you start delving into the word of Lagrange points, you will never be able to leave. Literally!!! This is because Lagrange points are positions where the gravitational pull of two large masses precisely equals the centrifugal force required for a small object to move with them. Which in Layman’s terms means, they are essentially pockets of no gravity where things aren’t influenced to leave. It is so cool! 

 

There are five Lagrange points, labeled Lagrange 1 through Lagrange 5. Out of the 5 Lagrange points 2 are stable and 3 are unstable. This is simply a metric of how strong the dead zone is. For example, L4 and L5 are at the apex of equilateral triangles with the two other vertices based on the two massive objects. These are the stable Lagrange points. The unstable Lagrange points 1, 3, and 5 lie along an imaginary line connecting the two massive objects. Lagrange point 1 being between the two objects, L2 being opposite the two massive objects on the side of the object of smaller mass, and L3 being outside the object of greater mass. 

For our purpose, we will assume that the two massive objects in question are the Sun and the Earth. In this scenario, L1 lies between the Earth and the Sun, closer to the Earth. This is the point where the Earth’s gravity and the Sun’s gravity are equivalent. This creates a space where the Earth and Sun pull equally on an object, keeping it stable and centered in the Lagrange point. 

 

L2 is on the opposing side of the Earth compared to L1. This is where the Sun and the Earth both pull the L point in the same direction. Now you might ask why the combined gravitational forces don’t move the L point towards them. This is because of centrifugal force. It is the same principle that explains why the clothes are always stuck to the side of the washing machine when it is done the spin cycle. Since the planets are always orbiting the Earth, the L point is always thrown outwards/away from the Sun. (Reference the centrifugal force diagram in the figure below) L2 is the point where the gravity of the Earth and Sun equal the tangential force created by L2’s orbit. This is the location where the JWST is located. It allows for the JWST to always be shielded from the Sun by the Earth, as well as keeping it in position due to the gravity in equilibrium. 

L3 is something that we as humans don’t know much about. It is only proven by math. Since L3 is on the other side of the Sun at all times, we have been unable to reach it. Because of its mysterious nature, it is often used in sci-fi novels and movies.

 

L4 and L5 are very similar. They use centrifugal force and the triangular pull of the Sun and Earth to keep them in place. These are considered to be stable Lagrange points because they are influenced by three different vectors. Centrifugal force is pulling the L point outwards, the Earth is pulling it towards itself, and the Sun is pulling it towards itself. This allows for the L point to be very consistent. This is seen due to the number of asteroids and space debris that are trapped there. L1, L2, and L3 aren’t as stable because they are only held in place by 2 vectors along the same axis. L4 and L5 are like pyramids standing up, when L1, L2, and L3 are like trying to stand on top of a pencil. 

 

And now you know about Lagrange points! It is super interesting how objects in the universe can create their own gravitational fields and even cancel others out. L points have provided unique ways to explore the solar system, and they will be a crucial part of exploration for years to come! Although make sure you don’t read too much about them, you might get stuck!

 

 

 

Works Cited:

Figure 1: https://solarsystem.nasa.gov/resources/754/what-is-a-lagrange-point/

Figure 2: https://microbenotes.com/centrifugal-force/