JWST Unveils the Cosmos

Back on Christmas Day, the massive James Webb Space Telescope finally launched. Over the last six months, we’ve watched as the telescope unfolded, drifted out to the L2 point and began powering up and focusing its instruments. Last night, the telescope unveiled its first image and, this morning, released three more. Go here for the full resolution images.

Behold:

The above image shows thousands of galaxies contained in a field the size of a grain of sand held at arm’s length. In the center, is the massive SMACS 0723 galaxy cluster, a collection of thousands of galaxies 5 billion light years away. But it also contains galaxies, the redder ones, that are much further away. JWST measured the distances of several galaxies in the field and found a bunch that were 13 billion light years away — placing them among the most distance galaxies we’ve ever seen. Because it has taken the light of these galaxies 13 billion years to reach us, we are seeing some of the earliest galaxies in the universe, newly born from the cosmic primordial soup. The spectra are so good that we will be able to measure the chemistry of those distant galaxies and test how our universe was enriched with heavy elements.

Those arcs and distortions? Those aren’t image artifacts. Those are background galaxies distorted by the powerful gravitational field of the foreground cluster. If you zoom in, you can actually see detail in those background galaxies — characteristics that were never visible until JWST stared at them. The depth of this image, obtained in 12 hour of JWST time, is something Hubble would take weeks to reach. And even then, it wouldn’t provide this kind of meticulous detail. Online astronomers are already doing little back-of-the-envelope evaluations of some of those galaxies based purely on the jpeg image.

I had to make a before and after to really appreciate how good the James Webb Telescope really is. pic.twitter.com/dj0HL8XGaZ

— Jason Short (@jason4short) July 11, 2022

The second image may not look as sexy, but it’s got it where it counts:

What you’re looking at is a spectrum — the light of a distant object broken down into a rainbow of color. But this isn’t a spectrum of a star or a galaxy. It’s of an exoplanet. In this case, a planet half the mass of Jupiter swinging around its sun every few days. As it passes in front of its star, the light from the star changes very minutely because the atmosphere of the planet absorbs some of the light. This spectrum shows it is absorbing wavelengths consistent with water vapor. And changes in the spectrum indicate this water vapor is cloudy or hazy, providing us a great deal of insight into what the planet is actually like. There will be a lot more of this, including studies of fainter smaller planets that are in the habitable zone of their planets. And JWST will get deeper images of objects like Wasp 96-b to find signatures of oxygen, methane, and carbon dioxide. We are now one step closer to discovering worlds like our own out there.

You’re seeing the future of our Solar System right there. A dying star is blowing out its outer layers, leaving a hot white dwarf behind. But you’ll actually two stars in that image. This star is a binary and JWST reveals both the dying white dwarf and the still alive main sequence star. Look at the extraordinary detail in those rings, the layers of dust and debris. That’s where new elements are being forged that will eventually coalesce into a new generation of planets.

That’s Stephan’s Quintet, which you might recognize from the opening of It’s A Wonderful Life. It is a group of four galaxies (and one foreground galaxy) that are interacting. Webb’s extraordinary resolution and imaging power reveal swirling gas and dust forming new stars in the wake of this cosmic trainwreck. Take an especially close look at that topmost galaxy. You’re seeing material being blown out by its central black hole as it gorges itself on material fed to it by the collision.

Wow! What you’re seeing is the edge of the Carina nebula. Massive stars are blowing back the shroud of gas and dust from which they were born and unveiling new smaller stars. This region was studies by HST as well but JWST, because of its extraordinary observing power and ability to pierce the veil of dust, reveals hundreds of newly-born stars. This is going to be one of JWST’s prime missions — studying how new star are formed and how they formed planets, a process that has been concealed from us until now.

What’s crazy is that these are just the JWST first images. These are objects that were known to be interesting that JWST studies to flex its muscles and warm up for the main event. Over the next few years, it will truly explore its capabilities, getting deeper more details images of objects after object. After a quarter of a century, we are finally getting the results of this massive project. And, already, they exceed our expectations.