Hubble images a pair of galaxies caught in the process of merging

By Georgina Torbet Published January 14, 2024

After last week’s image of the week from the Hubble Space Telescope showed a cluster of galaxies that appeared to be very close to each other but actually weren’t, this week’s image shows two images that are practically on top of each other. The two galaxies shown in the image below, NGC 6040 and LEDA 59642, are so close that they are interacting and have a shared name as a pair, Arp 122.

This NASA/ESA Hubble Space Telescope image features Arp 122, a peculiar galaxy that in fact comprises two galaxies – NGC 6040, the tilted, warped spiral galaxy and LEDA 59642, the round, face-on spiral – that are in the midst of a collision. — This NASA/ESA Hubble Space Telescope image features Arp 122, a peculiar galaxy that in fact comprises two galaxies – NGC 6040, the tilted, warped spiral galaxy and LEDA 59642, the round, face-on spiral – that are in the midst of a collision. ESA/Hubble & NASA, J. Dalcanton, Dark Energy Survey/DOE/FNAL/DECam/CTIO/NOIRLab/NSF/AURA Acknowledgement: L. Shatz

NGC 6040 is the galaxy on the top, which is stretched into a long, thin shape by the tremendous force of gravity from the rounder, face-on galaxy in the center-right, LEDA 59642. When galaxies come close together, the forces of gravity from both massive objects can interact and twist or distort one or both of the galaxies into unusual shapes, as has happened here.

Recommended Videos

The colliding of two galaxies is an epic event, and it can result in the destruction of one galaxy. At other times, the two colliding galaxies can merge into one. After hundreds of millions of years, the two can become one even larger galaxy, as may happen to Arp 122.

Please enable Javascript to view this content

“Galaxies are composed of stars and their solar systems, dust, gas, and invisible dark matter. In galactic collisions, therefore, these constituent components may experience enormous changes in the gravitational forces acting on them,” Hubble scientists explain. “In time, this completely changes the structure of the two (or more) colliding galaxies, and sometimes ultimately results in a single, merged galaxy. That may well be what results from the collision pictured in this image.”

Our own galaxy, the Milky Way, is scheduled to collide with our galactic neighbor, the Andromeda galaxy, in around four billion years. That collision would likely create a giant elliptical galaxy as a merger between the two.

However, another theory states that before that happens, the Milky Way could collide with a smaller satellite galaxy called the Large Magellanic Cloud in around two billion years’ time. This theory states that the forces of the two colliding galaxies could spur the supermassive black hole at the center of our galaxy into overdrive, causing it to swell in size and send out powerful jets of radiation.

Topics

Tech News

Georgina Torbet

Space Writer

Georgina has been the space writer at Digital Trends space writer for six years, covering human space exploration, planetary…

Space

James Webb spots another pair of galaxies forming a question mark

The galaxy cluster MACS-J0417.5-1154 is so massive it is warping the fabric of space-time and distorting the appearance of galaxies behind it, an effect known as gravitational lensing. This natural phenomenon magnifies distant galaxies and can also make them appear in an image multiple times, as NASA’s James Webb Space Telescope saw here.

The internet had a lot of fun last year when eagle-eyed viewers spotted a galaxy that looked like a question mark in an image from the James Webb Space Telescope. Now, Webb has stumbled across another questioning galaxy, and the reasons for its unusual shape reveal an important fact about how the telescope looks at some of the most distant galaxies ever observed.

The new question mark-shaped galaxy is part of an image of galaxy cluster MACS-J0417.5-1154, which is so massive that it distorts space-time. Extremely massive objects -- in this case, a cluster of many galaxies -- exert so much gravitational force that they bend space, so the light traveling past these objects is stretched. It's similar using a magnifying glass. In some cases, this effect, called gravitational lensing, can even make the same galaxy appear multiple times in different places within one image.

Space

Hubble images a pair of tiny dwarf galaxies

hubble dwarf galaxy pair ic3430 potw2431a 1

A new image from the Hubble Space Telescope shows a small dwarf galaxy called IC 3430 that's located 45 million light-years away. This galaxy is classified as both a dwarf galaxy, because of its small size, and an elliptical galaxy, because of its form.

Elliptical galaxies are smooth and featureless, appearing blob-like and diffuse, unlike spiral galaxies, like our Milky Way, which have a distinct structure of a central hub and stretching spiral arms.

Space

Hubble finds mysterious and elusive black hole

An international team of astronomers has used more than 500 images from the NASA/ESA Hubble Space Telescope spanning two decades to detect seven fast-moving stars in the innermost region of Omega Centauri, the largest and brightest globular cluster in the sky. These stars provide compelling new evidence for the presence of an intermediate-mass black hole.

An international team of astronomers has used more than 500 images from the NASA/European Space Agency (ESA) Hubble Space Telescope spanning two decades to detect seven fast-moving stars in the innermost region of Omega Centauri, the largest and brightest globular cluster in the sky. These stars provide compelling new evidence of the presence of an intermediate-mass black hole. ESA/Hubble & NASA, M. Häberle (MPIA)

There's something strange about black holes. Astronomers often find small black holes, which are between five times and 100 times the mass of the sun. And they often find huge supermassive black holes, which are hundreds of thousands of times the mass of the sun or even larger. But they almost never find black holes in between those two sizes.