Examining galaxies far, far away

The James Webb Space Telescope is shedding new light on the cosmos, one stunning image at a time

The image is divided horizontally by an undulating line between a cloudscape forming a nebula along the bottom portion and a comparatively clear upper portion. Speckled across both portions is a starfield, showing innumerable stars of many sizes. The smallest of these are small, distant, and faint points of light. The largest of these appear larger, closer, brighter, and more fully resolved with 8-point diffraction spikes. The upper portion of the image is blueish, and has wispy translucent cloud-like streaks rising from the nebula below. The orangish cloudy formation in the bottom half varies in density and ranges from translucent to opaque. The stars vary in color, the majority of which have a blue or orange hue. The cloud-like structure of the nebula contains ridges, peaks, and valleys – an appearance very similar to a mountain range. Three long diffraction spikes from the top right edge of the image suggest the presence of a large star just out of view.

NASA’s James Webb Space Telescope (JWST) is poised to revolutionize our understanding of the cosmos. From its current vantage point nearly a million miles beyond Earth’s orbit, the JWST has an unobstructed view of the expanding cosmos. Since it beamed its first images back to Earth in July 2022, the powerful telescope has stunned scientists and astronomy enthusiasts alike with its extremely high-resolution — and often achingly beautiful — images of galaxies far, far away.

Equipped with the largest primary mirror and the most powerful sensors ever sent into space, the JWST can peer much farther away — and much farther back in time — than its predecessor, the beloved (but increasingly obsolete) Hubble Space Telescope.

A black-and-white schematic illustration of the James Webb Space Telescope. Key components are labeled. The telescope features a kite-shaped base (which includes navigation and communication instruments, as well as a heat-resistant sunshield). A large circular mirror and a cluster of optical instruments is mounted perpendicular to the plane of the base.

A diagram of the James Webb Space Telescope identifying its primary components

The JWST’s sensors are optimized for the infrared spectrum, allowing the telescope to study the earliest galaxies and stars, and even the formation of planets well beyond the boundaries of our cosmic neighborhood.

Although the JWST has been operational for less than a year, it has already played an instrumental role in new cosmic discoveries — and its images are inspiring a new generation of astronomers, just as the Hubble did before it. This story breaks down some recent images captured by the JWST.


Wolf-Rayet 124

Image released March 24, 2023

This image shows the ring nebula M1-67, and the hot, bright star Wolf-Rayet 124 (WR 124) at its center. WR 124 is located some 15,000 light years from earth in the constellation Sagitta. It is around 30 times larger than our Sun, and 150,000 times as luminous.

Wolf-Rayet stars such as this one are a type of extremely massive, unstable, and luminous stars; they're also difficult to detect, as they only exist in an observable state for a short period of time.

As WR 124 ages, it sheds its outer layers of gas and dust. This stellar material is then carried outward by the star’s intense solar winds, creating WR 124’s wispy halo.

The veil of cosmic gas and dust that surrounds WR 124 is so thick that the star itself is only visible in the infrared spectrum. Fortunately, JWST’s near- and mid-infrared instruments can capture this star in unprecedented detail.

(Note that the “spikes” protruding from the stars in this image are not solar features, but visual artifacts produced by the telescope’s instruments.)

WR-124 is in its final stages of life, and will soon (in cosmic terms, at least) bow out of existence in a dramatic explosion known as a supernova. The solar matter that WR 124 ejects will eventually coalesce to form new stars — part of the endless cycle of cosmic regeneration.

Cassiopeia A

Image released April 07, 2023

Speaking of supernovas, this image captures the dazzling aftermath of a star’s death.

Cassiopeia A (Cas A) is a supernova remnant — in other words, the cosmic remains — of a stellar explosion that occurred 340 years ago. It is the second-youngest known remnant of an exploding star in our galaxy, and the strongest source of radio waves beyond our solar system.

This image was created by translating infrared data into the visible spectrum.

The pink filaments highlighted here are primarily composed of material cast off by the star during its death throes.

Scientists have given this green-tinted form a nickname: the Green Monster. "The shape and complexity are unexpected and challenging to understand," said Danny Milisavljevic, principal investigator of the Webb program capturing these images.

The death of a star is among the most dramatic cosmic events known to humankind. But images like this one remind us of the inherent beauty that exists despite — or perhaps because of — the violence of nature.

NGC 1433

Image released February 16, 2023

This overhead view of the spiral galaxy NGC 1433 is reminiscent of a spinning pinwheel. But whereas the quaint garden ornament is powered by wind, this galaxy's gyrations are driven mainly by the forces of gravity.

At the very center of this galaxy, a supermassive black hole voraciously sucks in material from the surrounding cosmic medium, creating an extraordinarily luminous zone known as the active galactic nucleus.

The bright clumps concentrated near the center of the galaxy, as well as on the fringes of its spiral arms, are dense formations of stars known as globular clusters. (And before you ask: yes, that's the technical term.)

Even though it is located some 46 million light-years from Earth, NGC 1433 can teach us a great deal about the structure and dynamics of our own galaxy.

A sea of galaxies

Image released January 31, 2023

Here, countless galaxies appear to tumble randomly through the vastness of space. But their movements are part of a cosmic ballet choreographed by the natural laws of the universe.

The large spiral galaxy in the foreground is designated LEDA 2046648 (and was evidently not named by the astronomer who coined “globular clusters”). It bears a striking resemblance to the Milky Way, but it's located a billion light years from Earth, in the constellation Hercules.

In other words, this image captures LEDA 2046648 as it appeared a billion years ago. Want to know what this galaxy looks like today? Unfortunately, you'll have to wait another billion years to find out. Nature doesn't like to be rushed.

Remarkably, LEDA 2046648 isn't even the oldest celestial object visible in this image. Some of the smaller red-tinted galaxies are believed to be around 13 billion years old — nearly as old as the universe itself!

These galaxies are so distant, and are receding so fast, that the light they emit has been stretched into the infrared range in a phenomenon known as redshift.

Fortunately, the JWST’s instruments are so sensitive that they can still resolve these galactic “dinosaurs” in striking clarity.

Each galaxy visible here contains around 100 billion stars. Considering an estimated 2 trillion total galaxies exist in the universe, it's difficult to imagine that Earth is the sole bastion of intelligent life.

Uranus

Image released April 6, 2023

The JWST is not solely concerned with cosmic affairs transpiring beyond our humble solar system. The telescope has also pointed its instruments toward our own cosmic neighbors, revealing subtle details.

This image of Uranus highlights the planet's characteristic rings and tilted orbit.

The image is so sharp that it captures the gaps between Uranus's individual rings.

Of the ice giant's 13 known rings, 11 are visible here. The remaining two are too faint for even JWST's gaze to capture, but astronomers are hopeful that the telescope may reveal them in the future.

At least six of the planet's 27 known moons are visible in this image.

Although Uranus is roughly 14.5 times as massive as earth, all of its moons are smaller than Earth's rocky satellite. The largest Uranian moon, , has a surface area comparable to that of Australia.

While distant galaxies, supernovae, and nebulae may capture our imagination with their dramatic forms and colors, images such as this one remind us that we still have much to learn about — and from — our cosmic neighbors.

Throughout history, humans have gazed at the night sky with wonder and curiosity, seeking to understand the mysteries of the universe. The James Webb Space Telescope, with its unparalleled observational capabilities, represents the latest chapter in the ongoing saga of human exploration of the cosmos.

Like its predecessors, the JWST continues to push the boundaries of our knowledge, with its breathtaking images shedding light on the cosmic mysteries that have absorbed astronomers for centuries. As the late astronomer Carl Sagan so eloquently put it, "we are a way for the cosmos to know itself" — and the James Webb Space Telescope is the proverbial mirror that enables this introspective inquiry.


Keep reading

About this story

This story was created with  ArcGIS StoryMaps , a digital storytelling tool. It draws inspiration from  this story , and uses images and information published by NASA.

Story

Cooper Thomas

Illustration

Warren Davison

A diagram of the James Webb Space Telescope identifying its primary components