A ghostly countenance is glaring back to us through 704 million light-years of interstellar space, in what’s actually a galactic collision of epic proportions.
With galaxies for eyes and rings of gas and dust for its face, the Arp-Madore system presents a truly haunting visage. The NASA / ESA Hubble Space Telescope captured this striking image back in June, but the fine folks at Hubble released this week in honor of Halloween and all things scary.
This system is scientifically interesting, aside from its ability to induce pareidolia—When we see faces in inanimate objects.
These two galaxies are heading straight towards each other in a slow-motion intergalactic head-on collision, rather than a glancing blow. The Arp-Madore system is also cool because the two galaxies are of roughly equal size. Most galactic collisions involve a larger object that subsumes a smaller one, according to Hubble.
We're also viewing this collision at a really fortuitous time. The forces involved in the collision have pulled the gas and dust outwards, forming a temporary ring-like structure. That in turn can fool our eyes into interpreting the shapes as a forehead, jawline, and nose. And of course the two galaxies are the “eyes.”
This ring will last for 100 million years (which isn't a long time in cosmological terms), and the galaxies will completely merge in about one to two billion years, after which time the ring will be long gone.
Galactic collisions are quite common, and we ourselves are poised for a similar celestial conflagration. In about 4 billion years, the Milky Way will collide with the Andromeda galaxy, in an event that will fundamentally alter the shape of both as the two galaxies will merge I become one.