The SDSS view in the infrared — with APOGEE — of the Milky Way galaxy as viewed towards the center. Image credit: SDSS / APOGEE.

What’s the largest galaxy in the Universe?

We’ve discovered some behemoths, but one outclasses them all.

“There is always a heavy demand for fresh mediocrity. In every generation the least cultivated taste has the largest appetite.” -Paul Gauguin

Our Milky Way contains some 400 billion stars, spanning 100,000 light years in diameter.

Galaxies come in a variety of types and sizes. While the Milky Way may be impressive from our location within it, it barely registers at all on a list of the largest galaxies. Image credit: Los Cumbres Observatory.

Yet compared to other galaxies, it’s not even especially large.

The Andromeda Galaxy resides in our local group, and is perhaps twice as large in diameter as our Milky Way. Image credit: Adam Evans / flickr.

In our own local group, the Andromeda galaxy is significantly larger, reaching 220,000 light years across.

Severely disrupted galaxies, like NGC 6872, can extend for many times farther than a quiet galaxy that hasn’t had a major gravitational interaction. Image credit: ESO / VLT, Judy Schmidt.

Interacting spiral galaxies can have their arms greatly extended and disrupted, with NGC 6872 spanning 522,000 light years from tip-to-tip.