On 25 December 2021, the James Webb Space Telescope was launched from Europe’s spaceport near Kourou, French Guiana on a Ariane 5 booster. The James Webb Space Telescope is a joint mission by NASA, the European Space Agency (ESA) and the Canadian Space Agency (CSA).

This launch will put the JWST on a course to the earth-sun L2 point where it will orbit the sun in a special position where the earth and sun’s gravity balance out, giving it a special view of the universe and a straight line-of-sight back to the earth (for its antenna).

The telescope, now fully deployed, will undergo a series of checks and calibrations over the next few months, while at the same time, the scientific instruments will gradually cool down to operating temperature. One very important task that needs to be completed is to get all the mirror segments precisely aligned and focused, and to ensure that the telescope can control its pointing and tracking.

Once fully deployed and checked out, the JWST will have one of the best views of the universe. With an objective diameter of 6.5m, it is the largest space telescope ever launched thus far. Its large light collecting area will enable the JWST to see the light from the galaxies so far away that the light takes more than 13 billion years to reach us. This also means that the JWST will be capable of picking up light from the earliest stars and galaxies, which will shed light on how the universe as we know it took shape.

The JWST will observe in infrared light instead of visible light. This is for a number of reasons. The universe is expanding, and the expansion of the universe stretches the light that distant galaxies emit. This also means that the light emitted from distant galaxies will be stretched into infrared by the time it reaches the JWST.

At the same time, infrared light is far less affected by dust, and that means that the JWST can also peer through the dust clouds from which stars and planets form. This will potentially allow us to catch planets in the act of forming.

The JWST has been many years in the making, having survived delays and budget cuts over the years. Now that it is on its way, it will be a very tense few months ahead before the first science data starts to come in.