There is good news from the astronomy and astrophysics community today as the James Webb telescope has now reached its final orbit and completed its deployment. It was launched on Christmas Day of 2021, but has been in development for thirty years already, and this summer all of that work and preparation will be paid off with the first of many new images of the distant reaches of the Universe.

In September 1989, before the now famous Hubble Space Telescope had even launched, astronomers around the world were already thinking about what would come next. Their original plan would have seen a 10m wide cooled telescope placed in a very high orbit, and capable of imaging in the three spectra of UV, visible light, and infrared. It soon became clear that that plan was a little too ambitious, and by the early 1990s the plan was revised to 6m telescope that would focus on visible and IR light. Eventually they settled on an 8m telescope with IR capabilities, with joint funding and development by NASA, CSA, and ESA, and would spend the rest of the 2000s and 2010s construction the precision electronics and mirror systems that would form the basis of the newest space telescope. And then on December 25, 2021, it was launched into orbit.

Now it is in its final orbit, located at the second Lagrange point. (The Lagrange points are locations where the gravitational forces of various bodies, such as the Earth and the Sun, are balanced so that satellites can stay in orbit with minimal fuel usage. In this case, the point is 1.5 million kilometers from Earth, and well beyond the orbit of the Moon. Unfortunately it is also unstable and so some additional fuel must be used to maintain orbit, but it will permit better quality viewing of the cosmos while also remaining close enough to Earth for easy communications. )

If everything continues to operate as expected, then the JWST will begin transmitting images back to Earth sometime this summer, and it could potentially bring a number of interesting scientific results in a short span of time. Because it can operate in the IR range, it will be able to study stars and galaxies that are obscured by dust, and allow us to view even older stars and galaxies than previously studied with the Hubble Space Telescope. It will also allow astronomers to study the mysterious brown dwarf objects, which seem to be massive glowing planets (or dim stars) that are not bright enough to be visible in the visual spectrum, but are expected to glow brightly in the infrared region. 

Another exciting scientific mission for the JWST will be the examination of the atmospheres of exoplanets. With the better quality imaging, larger mirrors, and infrared imaging capabilities, the JWST will allow us to study starlight passing through the atmospheres of distant planets. By examining the absorption lines of the light as it passes through those atmospheres, astronomers should be able to analyze the chemical composition of those worlds, and may even be able to detect the presences of water vapour. For the first time we might detect rainstorms on planets outside of our own Solar System. And where there is water, there could be life.

But for now we can celebrate the success of the James Webb Telescope as it ends its planning and deployment stage, and prepares for years of scientific missions and discoveries. It will be truly fascinating to see what amazing wonders of our Universe are about to be revealed.