Memory lane - JWST first photos

The hotly anticipated James Webb Space Telescope, the most powerful infrared telescope to date which was heralded to peer deeper into the cosmos than ever before, was launched into space on Christmas Day of 2021, after several years of delays. It was indeed the best present for thousands of people around the world - the result of a massive international collaboration of scientists, engineers, astronomers, programmers, designers and others who had spent years or even entire careers on this enormous project. Almost exactly two years ago in the summer of July 2022, the first images the telescope had taken were sent back, and they were indeed breathtaking. Already, images from this telescope have broken records, disproved theories, suggested new ones, and in some cases cracked open new mysteries for astronomers to scratch their heads about. It is fair to say the data pouring out of this instrument will keep a lot of people busy for a long time, and may reveal some extraordinary insights. Here I take a walk down memory lane to look at the very first photos that came out from Webb. Stay tuned for a follow up article on the second year anniversary photos coming soon!

STAR NURSERIES

Stars often form together in groups when dust clouds become so dense they collapse under gravity. This image shows thousands of stars in the Carina Nebula, a big dust cloud that formed roughly 3 million years ago, young in astronomy terms. The different colours represent different temperatures, caused by the stars' intense winds and ultraviolet radiation smashing into the surrounding gas. Counterintuitively, the blue parts are hottest while the red are coolest.  Since this image was taken in infrared, humans can't see this, however the different infrared 'colours' from the raw data have handily been translated by NASA's astronomers into human-friendly colours.

Carina Nebula, a hotbed of star formation. Image credit: NASA/ESSA/CSA/STScI

PROTOSTARS

This picture zooms in on one young star (protostar) in the catchily named L1527 cloud, much like the stellar nursery cloud above. The dark horizontal disk obscures the star's light, and the vertical jets (travelling hundred of kilometres per second) show the star's material shooting out and colliding with surrounding gas. Again, the dust is responsible for the colours, with the thinnest parts blue and the thickest, where the star's light is least likely to escape, in orange.

Protostar L1527, a young forming star. Image credit: NASA/ESA/CSA/STScI

GALAXIES

A galaxy is a collection of millions of stars attracted by gravity. These five different galaxies make up Stephan's Quintet, and this image is on a much larger scale than the previous ones. Tight galaxy groups like these are thought to have been more common in the early, hotter universe. This mosaic comprises almost 1000 individual telescopic images. The leftmost galaxy is much closer to us than the other four, at a distance of 40 million light years (compared to 290 million). The beautiful trails are made of gas, dust and stars being pulled by the gravity of other galaxies.

Stephan's Quintet, a group of five galaxies. Image credit: NASA/ESA/CSA/STScI

DYING STAR

And finally, we have the Southern Ring Nebula, a star at the end of its life having burnt through all its hydrogen and helium. Stars are sort of immortal, as once they 'die' their material is violently expelled in different directions, eventually calming down to form cold gaseous clouds, which several million years later (if sufficiently dense) form new stars, and the whole process restarts! 

Southern Ring nebula, the remnants of an exploded star. Image credit: NASA/ESA/CSA/STScI