Peruse the Largest Webb Space Telescope Image Taken to Date

For the James Webb Space Telescope, milestones have been unyielding. A little more than a month since this trailblazing machine left humanity in amazement following the release of its first astonishing deep field, its vivid nebular portraits and its shots of galactic muses, it’s endowed us with its largest image yet. 

This week, international scientists affiliated with the Cosmic Evolution Early Release Science Survey, or CEERS, presented an enormous, full-color mosaic born of data gathered by the JWST. It’s a record-breaking mural known as Epoch 1, and covers a small patch of sky near the handle of the Big Dipper constellation. 

Already, the CEERS collaboration has been revealing sneak peeks of Epoch 1, many of which have sent astronomers spiraling down the JWST discovery rabbit hole and publishing papers about galactic goodies within. For instance, CEERS project head Steven Finkelstein announced the submission of a paper last month regarding a «very convincing» candidate for a galaxy that could’ve existed only 290 million years post-Big Bang. It’s named Maisie’s galaxy, after his daughter, because it was discovered on her birthday.

But now, CEERS says Epoch 1 is officially complete. 

For context of how utterly big this final image is, the team explains that it covers an area about eight times as large as the JWST’s First Deep Field, released July 11, which was already mind-bendingly massive. The culminating mosaic consists of 690 individual frames taken with the JWST’s Near-Infrared Camera, and it’ll be built on by observations slated to take place in December.

«Epoch 1 covers less than half of our total survey area on the sky and already the images have led to new discoveries and an unexpected, but not unwelcome, abundance of never-before-seen galaxies,» the CEERS team said in a press release.

You can download either a medium- or high-resolution version of the picture here — but if you’re shooting for the latter, as I absolutely did, CEERS recommends using a computer or laptop. Because of how gigantic that file is, your mobile phone might start acting up. 

OK, now that you’ve successfully accessed the image, let’s discuss some highlights. There are six primary points of interest, according to the CEERS team. Here’s a diagram.

First, (1) there’s the spiral galaxy toward the top left, which exudes a redshift of z = 0.16. 

Redshift is essentially astronomers’ way of gauging how distant, and therefore back-in-time, an object is. It’s named for the fact that, as a luminous object slips farther from our vantage point, the light it emanates becomes redder and redder… and redder, eventually falling into the infrared region of the electromagnetic spectrum and becoming invisible to the human eye. Not to fear, though, because the JWST can collect that «invisible» light too, which is also why it promises to unveil an «unfiltered universe,» a phrase you might’ve seen tossed around online.

And in short, a greater redshift means something is farther away from Earth.

Next, (2) toward the center of the image is a bright galaxy with redshift of z = 1.05. This spot also holds several smaller galaxies that show up in an arclike format when viewed with the JWST. On Monday, Rebecca Larson, a University of Texas at Austin astronomy doctoral student and member of the CEERS collaboration, tweeted her adorable name for this scene. 

«TBT to one late night when I decided this galaxy…looked like Pacman and proceeded to overlay the little yellow dude and laughed so hard we all decided it was time to go home,» Larson wrote.

To the right of that gaggle, (3), is an interacting system of galaxies at z = 1.4. Finkelstein nicknamed this one the «Space Kraken,» Larson tweeted. It does weirdly resemble the scary ancient sea monster. 

Move over one more, (4), and you’ll notice a pair of spiral galaxies — in the enlarged version at the bottom of the diagram, a white arrow points to a supernova in this section of the sky also discovered by the JWST. Redshift here is z = 0.7. CEERS published a paper last month on these phenomena in particular, because comparing the JWST’s version of the duo to the Hubble Space Telescope’s might’ve offered lots of new information.

Below that, (5), is another special spiral galaxy at z = 0.7, and finally, (6), is a z = 0.63 galaxy with a tidal tail and grouping of red galaxies in the background that fall at z = 1.85. «I tried to call this feature a ‘hot mess of space,’ but the press people said ‘no,'» Larson tweeted about this chaotic landscape.

And of course, CEERS also highlights Maisie’s galaxy in a close-up diagram below. If Finkelstein and colleagues are right about this one existing 290 million light-years after the Big Bang, it has a staggering redshift of z = 14. Plus, it would basically prove that galaxies started forming much earlier in the universe than astronomers once thought.

However, due to the abundance of ultra-distant galaxy candidates being spotted since the JWST turned on, many scientists are guarding against the possibility of false hope. A paper published earlier this month in The Astrophysical Journal by CEERS collaborators, for instance, emphasizes the possibility of error when checking out these high redshift realms. Unrelated cosmic phenomena could basically be photobombing the data, and therefore contaminating results.

Nonetheless, the new era of astronomy that we find ourselves in is aggressively thrilling. 

«I hope you are just as awe-inspired and excited about this telescope and the data as I have been. I am so lucky to share them with you & hope you find your new favorite galaxies in them too!» Larson tweeted in conclusion to a brilliant thread on the CEERS map.