Skip to main content

An enormous galaxy cluster warps spacetime in this Hubble image

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.

This warping can have very useful effects, as it bends light coming from far-off objects. If a massive galaxy cluster sits between us and a faint, distant galaxy, then the gravitational lensing effect can act like a magnifying glass, making the light from the background object brighter. This allows astronomers to see some of the most distant — and therefore some of the oldest — galaxies in the universe.

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.
A massive galaxy cluster in the constellation Cetus dominates the center of this image from the NASA/European Hubble Space Telescope.  ESA/Hubble & NASA, H. Ebeling

In this Hubble image, the galaxy cluster SPT-CL J0019-2026 sits at the center. Located 4.6 billion light-years away, it is the mass of this huge cluster that creates the lensing effect, and you can see that the light from galaxies around the central cluster is stretched into elongated shapes as a result of the lensing. Without the lensing effect, these background galaxies would be too far away to see, so by taking advantage of the lensing effect, Hubble is able to see even further out into space.

This image was taken as something of a “bonus” image as part of a gap-filling project. Telescopes like Hubble receive far more applications from scientists who want to use them than can be accommodated, so time on a telescope is very precious. But there are sometimes small gaps in between different observations using the telescope, and researchers make the most out of this spare time by using it to observe interesting targets like this galaxy cluster.

Editors' Recommendations

Georgina Torbet
Georgina is the Digital Trends space writer, covering human space exploration, planetary science, and cosmology. She…
Hubble images the spooky Spider Galaxy
This image from the NASA/ESA Hubble Space Telescope shows the irregular galaxy UGC 5829.

This week's image from the Hubble Space Telescope shows an irregular galaxy, the spindly arms and clawed shape of which has led to it being named the Spider Galaxy. Located 30 million light-years away, the galaxy also known as UGC 5829 is an irregular galaxy that lacks the clear, orderly arms seen in spiral galaxies like the Milky Way.

This image from the NASA/ESA Hubble Space Telescope shows the irregular galaxy UGC 5829. ESA/Hubble & NASA, R. Tully, M. Messa

Read more
See what James Webb and Hubble are observing right now with this tool
james webb hubble live tracker screenshot 2024 03 06 220259

If you're looking for a relaxing way to peruse the fascinating sights of space on your lunch break, then a newly updated tool from NASA has you covered. The Space Telescope Live tools show the current targets of the James Webb Space Telescope and the Hubble Space Telescope, letting you browse the cosmos from the perspective of two of the hardest-working telescopes out there.

You can visit the web-based tools at WebbTelescope for the James Webb Space Telescope and HubbleSite for the Hubble Space Telescope. Clicking on a link will bring you to a portal showing the current and past observations of the telescope and a ton of detail about the observations.

Read more
Hubble spots a massive star forming amid clouds of dust and gas
This image from the NASA/ESA Hubble Space Telescope is a relatively close star-forming region known as IRAS 16562-3959.

A stunning new image from the Hubble Space Telescope shows the birth of a new, massive star at around 30 times the mass of our sun. Nestled with a nearby star-forming region called IRAS 16562-3959, the baby star is located within our galaxy and around 5,900 light-years from Earth.

You can see the sparkle of bright stars throughout the image, with the star-forming region visible as the orange-colored clouds of dust and gas stretching diagonally across the frame. These clouds are where dust and gas clump together to form knots, gradually attracting more dust and gas, growing over time to become protostars.

Read more