The scientific wonder behind James Webb’s first images

On July 11 and 12, 2022, humanity stepped into the future.

This near-perfectly aligned composite image shows JWST’s first deep-field view of the core of the SMACS 0723 cluster and contrasts it with the older Hubble view. Looking at the image details that are missing from the Hubble data but present in the JWST data shows us how much potential for discovery JWST scientists expect.

(Courtesy: NASA, ESA, CSA and STScI; NASA/ESA/Hubble (STScI); compiled by E. Siegel)

The James Webb Space Telescope (JWST) has released its first scientific images, revealing the universe in unprecedented light.

jwst deep field

This enhanced view of JWST’s first deep-field image of space overexposes the brightest galaxies and the center of the cluster to better bring out the details present in fainter, redder, and more distant galaxies. This first deep-field view took only half a day to obtain with JWST. With 20+ years of data to come, we can only imagine what will be revealed.

(Courtesy of: NASA, ESA, CSA and STScI; processing by E. Siegel)

The first image was a deep-field view of galaxy cluster SMACS 0723, whose gravity magnifies background objects.

A number of extremely different objects were revealed in the JWST image of SMACS 0723, and the power of spectroscopy allowed us to determine exactly how far away they are and how much their light is being stretched by the expansion of the Universe. This is a powerful demonstration of JWST’s capabilities as well as an illustration of the capabilities of gravitational lensing.

(Courtesy: NASA, ESA, CSA and STScI)

Containing objects from throughout space history, it visualizes even deeper, broader views ahead.

James Webb Hubble

A portion of Hubble’s extreme deep field imaged over a total of 23 days, contrasted with the simulated view expected by James Webb in the infrared. With upcoming large-area mosaics such as COSMOS-Web and PANORAMIC, the latter of which benefits from purely parallel observation, we need not only to break the space record for the most distant galaxy, but we need to learn what the earliest luminous objects in the universe appeared to be so.

(Credit: NASA/ESA and Hubble/HUDF team; JADES collaboration for the NIRCam simulation)

But three other targets were also observed with images, revealing unexpected, never-before-seen galaxies.

This three-panel image shows the “space rocks” view of the Carina Nebula as seen by Hubble (top), JWST’s NIRCam instrument (middle), and JWST’s MIRI instrument (bottom). With its first scientific publication, this new era in astronomy has indeed arrived.

(Courtesy: NASA, ESA, CSA and STScI; NASA, ESA and the Hubble Legacy Team (STScI/AURA))

The Carina Nebula, located in the Milky Way, is a dusty region rich in gas and stars.

Although difficult to identify by eye, there are numerous galaxies that can be seen poking through the clouds of the Space Rocks in the Carina Nebula. Many are manually framed here in the JWST NIRCam instrument cropped image.

(Courtesy: NASA, ESA, CSA and STScI, processing by E. Siegel)

But numerous galaxies appear through the obscuring matter.

On the less dusty side of the Space Rocks in the Carina Nebula, a number of faint, extended objects can be identified among the brilliant stars that populate most of this region of space. Even in the galactic plane, where the stellar density is greatest and neutral matter is abundant, background galaxies are abundant and likely to appear in virtually every subsequent JWST image.

(Courtesy: NASA, ESA, CSA and STScI, processing by E. Siegel)

Even in this dense region of our galaxy, the universe beyond can be glimpsed.

Overlaid with (older) Hubble data, the JWST NIRCam image of the Southern Ring Nebula is clearly superior in various ways: resolution, revealed detail, extent of outer gas, etc. This is truly a spectacular revelation about how stars like the sun end their lives.

(Courtesy: NASA, ESA, CSA and STScI)

The Southern Ring Nebula, a dying Sun-like star in our own galaxy, also reveals background sources.

Even when the debris from a dying star in our own galaxy is at its brightest and most feature-rich, numerous background galaxies can be identified, poking through the otherwise light-blocking dust at infrared wavelengths.

(Courtesy: NASA, ESA, CSA and STScI, processing by E. Siegel)

Some galaxies poke through the thin curves of the nebula.

Beyond the hazy structure of the Southern Ring Nebula, the abyss of empty space is revealed by JWST’s NIRCam imaging camera. A large number of galaxies and candidate galaxies can be identified even by hand. Many of these objects have never been seen before, demonstrating the power of JWST to reveal the previously unknown Universe, even when that is not the scientific goal of the imaging campaign.

(Courtesy: NASA, ESA, CSA and STScI, processing by E. Siegel)

Others richly occupy the space on its outskirts.

This unannotated portion of JWST’s NIRCam instrument view of the South Ring Nebula reveals the edges of the nebula, a series of multi-spiked stars, and a host of extended objects that can be identified as background galaxies. In every region of space imaged by NIRCam, galaxies await.

(Courtesy: NASA, ESA, CSA and STScI)

In every direction and place there is something spectacular to display.

This contrast of Hubble’s view of Stefan’s quintet with JWST’s NIRCam view reveals a series of features that are barely or not at all apparent with a shorter set of more restrictive wavelengths. The differences between the images highlight what features JWST can reveal that Hubble is missing. Despite the beauty and awe that this image provides, there are no known planetary systems, in our galaxy or any other, where humans could survive as we do on Earth.

(Courtesy: NASA, ESA and the Hubble SM4 ERO team; NASA, ESA, CSA and STScI)

But the image of Stephan’s Quintet from JWST was the most vivid.

Beyond the five main member galaxies that make up the Stefan Quintet, the JWST NIRCam view reveals thousands of additional galaxies that exist in the background, hundreds of which can be seen here and many of which have never been identified before by any other instrument or observatory .

(Courtesy: NASA, ESA, CSA and STScI)

Galaxies of all colors,

The colors and shapes of galaxies revealed here by JWST’s NIRCam are determined not only by the intrinsic color and shape of the galaxies and the stars inside them, but also by the cosmological redshift and cumulative distortion imprinted by all the foreground masses. The resolution of these background galaxies is unprecedented.

(Courtesy: NASA, ESA, CSA and STScI)


This extremely rich region of space was captured while observing the Stefan quintet with JWST’s NIRCam instrument. Many of these galaxies are clustered together in real space, while others are simply randomly aligned along the same line of sight. A cluster analysis of regions like this, many of which will be revealed in great detail by JWST, could provide a tremendous amount of additional science beyond what is planned.

(Courtesy: NASA, ESA, CSA and STScI)

and clustering patterns,

And just as there are many regions of space that have been imaged that are overdense in terms of the number of galaxies and the total mass in that region, there are also underdense void-like regions. JWST can pick them all up wherever it turns its infrared eyes.

(Courtesy: NASA, ESA, CSA and STScI)

can be seen everywhere.

This region, located on the outskirts of the star-forming regions caused by the interaction of multiple galaxy members in the Stefan quintet, reveals a wealth of detail about the nearby star formation in these galaxies, while also revealing background galaxies. The adage “one astronomer’s noise is another astronomer’s data” is on full display here, as extragalactic and stellar astronomers of all stripes can have a field day with what has been revealed in just this region of space.

(Courtesy: NASA, ESA, CSA and STScI)

We have long said that “one astronomer’s noise is another astronomer’s data”.

The MIRI view of Stephan’s Quintet demonstrates features that cannot be seen at any other wavelength. Its top galaxy – NGC 7319 – harbors a supermassive black hole with a mass 24 million times that of the Sun. It is actively accreting material and emitting light energy equivalent to 40 billion suns. MIRI sees through the dust surrounding this black hole to reveal the strikingly bright active galactic nucleus. It is so bright to MIRI’s eyes that it even has the characteristic JWST “spike” pattern.

(Courtesy: NASA, ESA, CSA and STScI)

For galaxy scientists, every upcoming JWST image holds a potential treasure trove.

James Webb spikes

The first fine-phase image ever released from NASA’s James Webb Space Telescope shows a single image of a star full of six prominent diffraction spikes (and two less prominent ones), with background stars and galaxies revealed behind it. The background galaxies were a surprise to astronomers; JWST images the universe with roughly twice the precision of the performance for which it was designed. Even images like this, not originally intended for scientific purposes, can prove useful to astronomers studying the universe as a unique and unexpected source of data.

(Credit: NASA/STScI)

Primarily, Mute Monday tells an astronomical story in images, visuals and no more than 200 words. Talk less; Smile more.

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