It turns out that if two galaxies of just the right masses line up in just the right ways, you get a grand design spiral. But if things are just wrong, you get what looks like a lightning bug splatting to its death in the sky.

The Arp 143 system consists of two galaxies. One is a blob of reddish light that is distorted through its interactions with its nature. This is NGC 2444. That red color indicates it is dominated by older stars, at least for now.

The other system, consecutively cataloged as NGC 2445, consists of a round core of light surrounded by a massive triangle of star formation. Triangles aren’t a typical shape for galaxies, and in this case, the shape is created by the pull of the red round NGC 2444. It’s thought these systems passed through one another, triggering the star formation and allowing NGC 2444 to pull material with it as it escapes.

Newly released images from the Hubble Space Telescope are allowing researchers to tease out new details in this collision. Specifically, Hubble’s image reveals dark webs of gas and dust blocking light from the star-forming NGC 2445’s core. These structures were formed by outbursts of material and are backlit by stars that have formed in just the past million or so years.

This kind of beautiful destruction is just one step in a multi-billion-year merger process that will eventually bring these two systems together to form one larger galaxy, one likely devoid of new stars. We are witnessing one final gasp of star birth before the system settles into a long red future.

More Information

ESA Hubble press release

Hubblesite press release