Skip to main content

One galaxy, two views: Webb and Hubble take on the same target

The Hubble Space Telescope and the James Webb Space Telescope are both powerful tools for peering out into the cosmos, but the way they view the universe is quite different. While Hubble primarily looks in the visible light wavelength in the same range as the human eye, Webb looks in the infrared range which is beyond human vision. Looking at the same object in different wavelengths reveals different features, as a recently released pair of image demonstrates.

Webb and Hubble both imaged the spiral galaxy IC 5332, located over 29 million light-years away. Though this galaxy is only about one-third of the size of the Milky Way, it makes a great target for astronomy because the spiral is almost perfectly face-on from our point of view. The image captured by Webb’s ultra-cool MIRI instrument shows the skeletal-like structure of the galaxy’s spiral arms.

Related Videos
This image of the spiral galaxy IC 5332, taken by the NASA/ESA/CSA James Webb Space Telescope with its MIRI instrument, has been scaled and cropped to match the NASA/ESA Hubble Space Telescope’s view of the same galaxy.
Image of the spiral galaxy IC 5332, taken by the NASA/ESA/CSA James Webb Space Telescope with its MIRI instrument. ESA/Webb, NASA & CSA, J. Lee and the PHANGS-JWST and PHANGS-HST Teams

Compare this image to an image taken by Hubble, which shows dust as dark patches blocking out light through the spiral arms.

The winding spiral structure of the galaxy IC 5332 is portrayed in amazing detail by this image from the NASA/ESA Hubble Space Telescope. The clarity of Hubble’s Wide Field Camera 3 (WFC3) separates the arms of the galaxy from dark patches of dust in between, which block out the ultraviolet and visible light Hubble is sensitive to. Younger and older stars can be differentiated by their colours, showing how they are distributed throughout the galaxy. Meanwhile, Webb’s MIRI image provides a very different view, instead highlighting the patterns of gas spread throughout the galaxy.
The winding spiral structure of the galaxy IC 5332 is portrayed in amazing detail by this image from the NASA/ESA Hubble Space Telescope. The clarity of Hubble’s Wide Field Camera 3 (WFC3) separates the arms of the galaxy from dark patches of dust in between, which block out the ultraviolet and visible light Hubble is sensitive to. Younger and older stars can be differentiated by their colors, showing how they are distributed throughout the galaxy. Meanwhile, Webb’s MIRI image provides a very different view, instead highlighting the patterns of gas spread throughout the galaxy. ESA/Webb, NASA & CSA, J. Lee and the PHANGS-JWST and PHANGS-HST Teams

On the ESA Webb website there is a slider which lets you compare the two images directly and see the similarities and differences that they observe when looking at the same galaxy.

The reason the galaxy looks so different in visible light versus infrared is to do with the dust spread throughout it, as the European Space Agency explains: “Ultraviolet and visible light are far more prone to being scattered by interstellar dust than infrared light. Therefore dusty regions can be identified easily in the Hubble image as the darker regions that much of the galaxy’s ultraviolet and visible light has not been able to travel through. Those same dusty regions are no longer dark in the Webb image, however, as the mid-infrared light from the galaxy has been able to pass through them.”

Editors' Recommendations

An enormous galaxy cluster warps spacetime in this Hubble image
A massive galaxy cluster in the constellation Cetus dominates the centre of this image from the NASA/ESA Hubble Space Telescope. This image is populated with a serene collection of elliptical and spiral galaxies, but galaxies surrounding the central cluster — which is named SPT-CL J0019-2026 — appear stretched into bright arcs, as if distorted by a gargantuan magnifying glass. This cosmic contortion is called gravitational lensing, and it occurs when a massive object like a galaxy cluster has a sufficiently powerful gravitational field to distort and magnify the light from background objects.

Every week, scientists using the Hubble Space Telescope share an image from this beloved piece of space technology, and this week's image shows a vital astronomical phenomenon in action. While space telescopes can observe very far-off objects if they are bright enough, there is still a lot of the universe that is too far away to observe -- which is why researchers make use of a natural occurrence called gravitational lensing.

Gravitational lensing happens when an object like a galaxy or galaxy cluster has so much mass that it noticeably warps spacetime. Everything with mass bends spacetime somewhat, but usually this effect is so small as to be effectively invisible. But when the object is something with as much mass as a large galaxy or even a collection of galaxies, then this warping can be significant enough for us to observe it.

Read more
James Webb spots ‘universe-breaking’ massive early galaxies
Images of six candidate massive galaxies, seen 500-700 million years after the Big Bang. One of the sources (bottom left) could contain as many stars as our present-day Milky Way, according to researchers, but it is 30 times more compact.

The James Webb Space Telescope continues to throw up surprises, and recently it has been used to spot some very old galaxies which have astonished astronomers. The galaxy candidates are far more massive than anyone expected would be possible, challenging assumptions about the early universe.

An international team of astronomers spotted six potential galaxies in a region of space close to the Big Dipper constellation from just 500 to 700 million years after the Big Bang, when the universe was still in its infancy. “These objects are way more massive​ than anyone expected,” said one of the researchers, Joel Leja of Penn State. “We expected only to find tiny, young, baby galaxies at this point in time, but we’ve discovered galaxies as mature as our own in what was previously understood to be the dawn of the universe.”

Read more
Webb uses a galactic megacluster as an enormous magnifying lens
Astronomers estimate 50,000 sources of near-infrared light are represented in this image from NASA’s James Webb Space Telescope. Their light has travelled through varying distances to reach the telescope’s detectors, representing the vastness of space in a single image. A foreground star in our own galaxy, to the right of the image center, displays Webb’s distinctive diffraction spikes. Bright white sources surrounded by a hazy glow are the galaxies of Pandora’s Cluster, a conglomeration of already-massive clusters of galaxies coming together to form a megacluster.

Modern space telescopes are tremendously powerful instruments, able to look deep into space without being limited by the blurring effects of Earth's atmosphere. But even this is not enough to allow them to see the most distant galaxies, which are so far away that looking at them is like looking back in time to the early stages of the universe.

To look even further out, astronomers take advantage of a phenomenon called gravitational lensing. This happens when an object like a galaxy or a galaxy cluster has so much mass that it bends space-time, acting like a magnifying glass and brightening the extremely distant objects behind it.

Read more