Even though galaxies are widely spaced in the universe, they do bump into each other in a cosmic mashup. The dust lanes of NGC 7174, middle right, are mangled to form the letter “M” in this image from NASA‘s Hubble Space Telescope.
Zoom out and explore the image. A mangled spiral galaxy hangs between two elliptical galaxies in the image. The three galaxies, NGC 7173, NGC 7174 and NGC 7176 are part of what astronomers call the Hickson Compact Group. The group of galaxies is named after astronomer Paul Hickson who first cataloged the galaxies in the 1980s. The Hickson Compact Group contains a tight group of about 16 galaxies, many of them dwarf galaxies similar to the Large and Small Magellanic Clouds.
Explore the warped structure of the spiral galaxy caught in the middle. What shapes can you pick out in the dark dust lanes of the the galaxies? I see a dragon, salamander or sea horse. Do you see background galaxies as you wander in the image?
NGC 7173 and NGC 7176 seem to be normal elliptical galaxies without much gas and dust. The spiral galaxy in the center may have once had a pinwheel shape like our own Milky Way Galaxy. Now it is caught in the mashup. Its spiral arms and dust lanes are being stretched and distorted by gravity. Because spiral galaxies are full of gas and dust, new star formation will occur over the next million years. Gas and dust is stretched into strands as gravity tugs on the galaxy. The gas and dust bunch together in these strands and will eventually collapse into new stars. Eventually the spiral galaxy of NGC 7174 will be swallowed up by the pair of elliptical galaxies. The elliptical galaxies will join as well creating a huge super-galaxy.
This galaxy mashup lies about 100 million light years from Earth toward the constellation of Piscis Austrinus, the Southern Fish.