Watch: The scale of the entire Universe versus JWST’s views

In July of 2022, JWST’s eyes unveiled the Universe.

This side-by-side view of galaxy cluster SMACS 0723 shows the MIRI (left) and NIRCam (right) views of this region from JWST. Note that although there’s a bright galaxy cluster at the center of the image, the most interesting objects are gravitationally lensed, distorted, and magnified by the cluster itself, and are located far more distant than the cluster itself.

Even familiar objects showed details never previously revealed.

This contrast of Hubble’s view of Stephan’s Quintet with JWST’s NIRCam view reveals a series of features that are barely apparent or not obvious at all with a shorter set of more restrictive wavelengths. The differences between the images highlight what features JWST can reveal that Hubble misses.

JWST’s superior resolution and greater wavelength coverage outclass even Hubble.

Compared to the old Hubble view of this portion of galaxy cluster SMACS 0723, the JWST view is sharper, spans a greater range of wavelengths, and unveils and resolves fainter and more distant objects than ever before. Details that have never been seen or measured before in the Universe are suddenly available to us all.

With long-exposure times, it’s already revealed record-breaking faint, distant objects.

The viewing area of the JADES survey, along with the four most distant galaxies verified within this field-of-view. The three galaxies at z = 13.20, 12.63, and 11.58 are all more distant than the previous record-holder, GN-z11, which had been identified by Hubble and has now been spectroscopically confirmed by JWST to be at a redshift of z = 10.6. No doubt these records will themselves be broken, possibly with galaxy candidates that already exist within the same field-of-view.

But one limitation it possesses is a very narrow field-of-view.

This animation showcases JWST’s unique near-infrared views of Jupiter. In addition to the bands, the great red spot, and the “atmospheric haze” visible at the day/night boundary of Jupiter, a number of moon, ring, and auroral features are seen and labeled. A single NIRCam or MIRI frame is just barely large enough to hold all of Jupiter’s disk within it, enabling spectacular views of this world with JWST. With an expected lifetime to last until the mid-2040s, JWST will observe multiple Jovian solstices and equinoxes, but won’t last until Uranus reaches its equinox phase.

It would take 16.3 million NIRCam images to cover the entire near-infrared sky.

This illustration shows the different types of images that can be obtained with each of JWST’s instruments and observing modes, and highlights the total viewing area and other specifications inherent in each instrument. Note the disconnected field-of-view of NIRCam, and how NIRSpec observes a different region of space when NIRCam is targeted on a specific region.

The mid-infrared is even worse, requiring 63.9 million MIRI images to cover the full Universe.

This multi-paneled image shows the details returned by each of the JWST’s instruments in the same pointing/field-of-view during its commissioning in the first half of 2022. For the first time, in late April of 2022, all of the instruments across the full field-of-view were properly and fully calibrated, bringing JWST one step closer to being ready to begin science operations. Although JWST and its instruments give us a truly world-class space-based observatory, this technology is “frozen in,” and cannot have its instruments upgraded the way we can upgrade instruments easily and cheaply on ground-based telescopes.

Larger regions of space can be imaged by JWST, but there’s a cost.

Preliminary total system throughput for each NIRCam filter, including contributions from the JWST Optical Telescope Element (OTE), NIRCam optical train, dichroics, filters, and detector quantum efficiency (QE). Throughput refers to photon-to-electron conversion efficiency. By using a series of JWST filters extending to much longer wavelengths than Hubble’s limit (between 1.6 and 2.0 microns), JWST can reveal details that are completely invisible to Hubble. The more filters that are leveraged in a single image, the greater the amount of details and features that can be revealed.

Many adjacent and overlapping images need to be taken, spanning several different wavelengths.

This 10-frame animation shows each individual filter used to view the same region of the Large Magellanic Cloud (LMC), with an assigned color RGB composite used to bring out various features available to MIRI’s unique view. The final-frame image showcases the full composite in RGB color; despite having more filters than human eyes can process, the data provides scientific information well beyond what our eyes can comprehend.

They then need to be stitched together: creating a mosaic without gaps.

This image shows the region of study of the JWST Advanced Deep Extragalactic Survey (JADES). This area includes and contains the Hubble eXtreme Deep Field and reveals new, record-breakingly distant galaxies that Hubble could not see.

Revealing greater detail requires longer exposures, monopolizing JWST’s observing time.

This three-panel animation shows three different views of the center of the Phantom Galaxy, M74 (NGC 628). The familiar color image is the Hubble (optical) view, the second panel showcases near-infrared views from both Hubble and Webb, while the mid-infrared panel shows the warm dust that will eventually form new stars at a later time, containing data from JWST alone.

But the science, and the associated sights, are well worth it.

The Hubble vs. JWST views of the Cartwheel galaxy (and its surroundings) showcase a spectacular difference: the 1995 vs. 2022 images reveal how foreground objects, like interloping stars from within our own galaxy, have moved relative to the background features in these external galaxies over the past 27 years. In addition the JWST data reveals features that Hubble could never see.

It’s incredibly impressive to see even a tiny part of the Universe in such great detail.

Over the timespan of 27 years, our view of the Pillars of Creation has not only expanded in size and resolution, but also in terms of wavelength coverage. The longer-wavelengths of light, as revealed in unprecedented resolution by JWST, allow us to see features that could never be exposed by an optical telescope, even one in space, on its own. We can also tell, although the effect is subtle, that the Pillars are slowly evaporating, and that after ~100,000 years or so, they will be completely gone.

Inspired by this, visual artists at Perihelion created videos showing iconic JWST images, to scale, within the Universe.

This three-panel image shows the view of the Carina Nebula’s “cosmic cliffs” as seen by Hubble (top), JWST’s NIRCam instrument (middle), and JWST’s MIRI instrument (bottom). With its first science release in July of 2022, a new era in astronomy has truly arrived.

You can tour the famed Cosmic Cliffs,

the Southern Ring Nebula,

and Stephan’s Quintet,

while appreciating the enormity of the Universe.

This view of Pandora’s Cluster, also known as Abell 2744, was constructed from mosaics covering 0.007 square degrees on the sky with 6 different wavelength filters from JWST’s NIRCam imager. Over 50,000 sources were revealed in this mosaic, which still covers just 1-5.6 millionth of the sky.

Imagine what else is out there, just waiting to be revealed.

This spiral galaxy, whose central supermassive black hole is revealed with JWST, represents just 0.8% of the mosaic released of Pandora’s Cluster, Abell 2744, from JWST. This deep view corresponds to only 1-700 millionth of the sky. If JWST could construct an image like this in a single minute, it would need to operate until the year 3354 to cover the entire sky.

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