After many days of travel and tension, the James Webb Space Telescope will be arriving at its final destination, the Lagrange Point known as L2.

The ground team is preparing to fire Webb’s thrusters to insert the telescope into its orbital path some one million miles from Earth. The thrusters are set to fire at around 21:00 local time but NASA won’t be broadcasting the event as it happens.

While the thruster burn has been planned for a while now, it’s likely to be a tense few moments for the ground team considering how long this project has taken to reach this point.

The spacefaring firm has said that it will host a teleconference after the fact but we will likely only hear details of the conference later this evening or in the wee hours of Tuesday morning.

Why L2?

The spot NASA and the ESA have selected for the JWST to live out its days in an interesting one for several reasons.

Lagrange points are created when two massive bodies orbit each other, in this case the Earth and the Sun. The phenomenon creates points of gravitational stability in the system around the bodies and the one JWST is headed to is located in Earth’s shadow.

“While all Lagrange points are gravitational balance points, not all are completely stable. L1, L2, and L3 are ‘meta-stable’ locations with saddle-shaped gravity gradients, like a point on the middle of a ridgeline between two slightly higher peaks wherein it is the low, stable point between the two peaks, but it is still a high, unstable point relative to the valleys on either side of the ridge. L4 and L5 are stable in that each location is like a shallow depression or bowl atop the middle of a long, tall ridge or hill,” NASA explains.

We highly recommend giving the video below a watch for a more thorough explanation of Lagrange points.

That’s the second reason the position is interesting because in order for JWST’s observatory to see the infrared light emitted from the beginnings of the universe, it can’t experience interference from the Sun. The heat shield will help in this regard but the shadow of the Earth will help even more given how far heat can travel in the void of space. In fact, NASA was so concerned about heat it even factored the heat Earth generates into its plans.

Essentially then, NASA and the ESA are playing a balancing game although to be fair, it is on a cosmic scale.

After many years the JWST is set to kick into action soon and we can’t wait for what discoveries it enables.

If you’d like to learn more about Lagrange points and why NASA selected L2 you can read more here.