Monday Astronomy Picture Ponderings (MAPPs) 6/20/2022

Spiral, Elliptical, and Irregular Galaxies, Oh My!

The galaxies in our universe and how to explore them!

Spiral galaxy NGC 1566 from Astropix. Credit: Dark Energy Survey/DOE/FNAL/DECam/CTIO/NOIRLab/NSF/AURAImage processing: T.A. Rector (University of Alaska Anchorage/NSF’s NOIRLab), J. Miller (Gemini Observatory/NSF’s NOIRLab), M. Zamani & D. de Martin (NSF’s NOIRLab) Image Use Policy: Creative Commons Attribution 4.0 International License

Welcome back to the Monday Astronomy Picture Ponderings (MAPPs) series where every Monday I normally pick one of NASA’s Astronomy Picture of the Day (APOD) entries from the past seven days to focus on in some way.

On June 13th, 2022, NASA’s Astronomy Picture of the Day featured an absolutely beautiful copyrighted image of M51, the Whirlpool Galaxy from the Hubble Space Telescope. I’ve featured galaxies before in this series and wanted to take this opportunity to give a nice overview of galaxies, including how you can learn more about them and even contribute to scientific research.

Since the image is copyrighted and the creators deserve credit for their work, I encourage you to check out the link above to see the image featured on the 13th, but for this article, we will be utilizing galaxy images from Astropix, an amazing repository of free-to-use images from some of the best telescopes around the world.

What is a galaxy?

“Galaxies are vast cosmic islands of stars, gas, dust, and dark matter held together by gravity.” — Galaxies, NASA Hubblesite