Today, President Joe Biden revealed the first full-color scientific image from the JWST, the biggest and most powerful observatory ever launched into space. Last week NASA teased the five targets for the first scientific work the telescope has been conducting, and now the very first image showing the galaxy cluster SMACS 0723 has been released and we are in awe.
JWST can peer deeper into the universe than any telescope that has come before it. At a cost of around $10 billion dollars and after 14 years of delays, we are finally seeing what it is capable of.
This is the highest resolution image of the infrared universe ever taken. The choice of SMACS 0723 as one of the first targets makes sense given that it fits perfectly with JWST's study of the early universe, one of the Science Themes that have been chosen for the telescope.
JWST's impressive eye will look deeper into the universe than any observatory before it, which means looking back into the past given that the speed of light is finite. At the limit of what it can see are the first galaxies and stars.
Help in this investigation of the early universe comes in the form of gravitational lensing. This happens when a massive foreground object warps the light of distant galaxies behind it, magnifying them and making them easier to study.
One such lens is SMACS 0723, a galaxy cluster known for its incredible mass located 4.6 billion light-years away. It is a perfect lens for the galaxies that existed 13.5 billion years ago, visible in the image as arcs or multiple images of the same galaxy.
Hubble has studied many such systems and JWST will certainly do the same.
Four more images will be released tomorrow covering every aspect of the observatory's scientific themes. It's important to state that this really is just the beginning. Astronomers and scientific institutes worldwide will get data from JWST that will expand our knowledge of the early universe like nothing before, and the excitement is palpable.
“My team and our collaborators are primarily interested in using JWST to identify and study the most distant galaxies in the Universe. We will be seeing these when the Universe was very young and some of them may be forming stars for the very first time," Dr Stephen Wilkins from the University of Sussex, UK told IFLScience.
"Really crucially with Webb we will not only find them but also measure their detailed properties, including how “enriched” they are with heavy elements.”
When asked why JWST is going to be revolutionary for this work, Dr Wilkins had the answer ready: “It’s the combination of sensitivity (due to a bigger telescope in space), wavelength range (Webb extends much further into the infrared than Hubble), and that it can also do spectroscopy, which is crucial e.g. to measure chemical abundance’s.
"Any one of these would be revolutionary, but we have all three.”
With today's very first image released, a new chapter in astronomy has begun.