A state-of-the art new camera in Chile has produced a stunning 100 megapixel image of two galaxies dramatically interacting with each other.
The galaxies we see now are the result of mergers like this. Precisely how galaxies form is a mystery, but we do know that these vast seas of stars often interact and mix to form something new—and bigger. Such mergers also kick-start the birth of new stars.
Captured by the Dark Energy Camera (DECam) on the NSF’s NOIRLab’s Víctor M. Blanco 4-meter Telescope at Cerro Tololo Inter-American Observatory in Chile, the image shows two galaxies that exist a whopping 40 million light-years distant. Barred spiral galaxy NGC 1512 (at the center of this article’s main image, above) and the much smaller NGC 1510 are in the constellation of Horologium. It can only be seen from the southern hemisphere.
The two galaxies have been crashing into each other for the last 400 million years, a process that has created millions of stars.
Check out wispy tendrils of the larger galaxy that swarm around the smaller galaxy. You can also see a bridge of stars that join the two galaxies, which is the evidence we have that they are indeed interacting with each other.
It’s thought that all disc galaxies, including the Milky Way, formed through collisions and mergers. Like NGC 1512, the haloes of galaxies have faint streams and shells of stars, left by merging satellite galaxies, and star clusters scattered in their outskirts.
For example, the Milky Way is 13.5 billion years old and is thought to have merged with the Gaia-Enceladus-Sausage galaxy (no kidding!) about nine billion years ago. That’s thought to be only its biggest collision event, though it’s possible there was another ancient collision with the Kraken galaxy.
The Gaia mission—a satellite launched in 2013 to map and characterize more than one billion of the stars in the Milky Way—has already revealed that our galaxy’s halo is full of debris from some massive dwarf galaxies.
What will happen next to NGC 1512 and NGC 1510? They’ll eventually merge into one larger galaxy and, ultimately, form a new galaxy that will go on to merge with others.
Wishing you clear skies and wide eyes.