Stare into space long enough, with strong enough eyes at many wavelengths, and eventually you find things that look like the events happening in this image. This is an action shot, capturing a scene from the evolution of a galaxy. A supermassive black hole at the heart of the galaxy is devouring material. This accretion produces vast amounts of energy that outshine the light from all the stars in the galaxy. The surrounding gases are “excited” by the action, resulting in ionization. Light at a specific wavelength is emitted, allowing astronomers to see it.

When we say it’s an exciting universe, we aren’t just talking about cool stuff happening. The processes that heat gases and cause light to shine out across the parsecs so we can see it belie some of the most interesting and energetic events in the cosmos. Astronomy seeks to understand those processes and events. And that’s why snapshots like this one are so important. Build up enough of them and you start to get a feel for what’s happening in the cosmos–and why.