James Webb Space Telescope: How the spacecraft will now help us peer into the secrets of the universe

Nasa’s James Webb Space Telescope has finally arrived in its long-imagined spot, and will finally start surveying the very beginning and end of the cosmos.

The spacecraft is now hovering at the Lagrange Point 2, or LP2, which is about a million miles Earth, facing its nightside. It arrived there with a short thruster burn, and will stay there – since the advantage of Lagrange Points is that the gravity is neatly balanced, allowing objects to float there.

The space telescope lifted off from Earth 30 days ago and has been making its way to the spot ever since. But in another sense the journey has been even longer: development initially began in 1996, and its launch was repeatedly delayed.

Now it is there, scientists will start by getting the telescope ready. That will include starting up its instruments and fine-tuning the various mirrors that make up the telescope itself, before the first images come in June.

When those images start to arrive, Nasa hopes they illuminate the very history of the cosmos, looking into nearby galaxies to understand how stars form, what powers the movement of the universe and whether other planets could host alien life.

It will be able to do that by looking deep into the universe. As it does so, it will be able to see light that comes from when the cosmos was much younger – letting it see the first stars and galaxies as they form.

The telescope will also be able to “sniff” planets, allowing it to understand their chemical makeup. That could help characterise distant planets, and allow scientists to understand better whether they might be habitable.

All of that work is expected to last years. While the minimum time was set at five years, everything has gone so well so far that it has used less fuel than expected – and engineers say that it might be able to keep enough fuel to do its work for some 20 years instead.