A galactic collision of two galaxies which began more than 300 million years ago, NGC 520 is actually made up of two disk galaxies which will eventually merge together to form one larger, more massive system. NGC 520 was discovered by William Herschel in 1784 and is one of the largest and brightest galaxies in the Siena Galaxy Atlas. Credit: CTIO/NOIRLab/DOE/NSF/AURA/Acknowledgment: PI: J. Moustakas (Siena College)/Image Procesing: T.A. Rector (University of Alaska Anchorage/NSF’s NOIRLab) & M. Zamani (NSF’s NOIRLab) & D. de Martin (NSF’s NOIRLab)

Thousands of colorful spirals, warm blobs and razor-thin ellipticals populate the National Science Foundation’s Noirlab atlas.

The atlas, named the Siena Galaxy Atlas, uses the data from three Dark Energy Spectroscopic Instrument Legacy Surveys taken between 2014 and 2017. Cerro Tololo Inter-American Observatory and Kitt Peak National Observatory collected data on the 383,620 nearby galaxy targets in the 20,000 square degree area – roughly half of the visible sky – making it one of the largest surveys ever conducted.