March 24 Astronomy Picture of the Day

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

2022 March 24

The overdeveloped spiral arm of the galaxy NGC 772, which was created by tidal interactions with an unruly neighbor, dominates this observation made by astronomers using the Gemini North telescope located near the summit of Maunakea in Hawai‘i.

Arp 78: Peculiar Galaxy in Aries

Image Credit & License: International Gemini Observatory / NOIRLab / NSF / AURA
Processing: T.A. Rector (Univ. Alaska Anchorage), J. Miller (Gemini Observatory/NOIRLab), M. Zamani & D. de Martin

Explanation: Peculiar spiral galaxy Arp 78 is found within the boundaries of the head strong constellation Aries. Some 100 million light-years beyond the stars and nebulae of our Milky Way galaxy, the island universe is over 100,000 light-years across. Also known as NGC 772, it sports a prominent, outer spiral arm in this detailed cosmic portrait from the large Gemini North telescope near the summit of Maunakea, Hawaii, planet Earth. Tracking along sweeping dust lanes and lined with young blue star clusters, Arp 78’s spiral arm is likely pumped-up by galactic-scale gravitational tidal interactions The close companion galaxy responsible is NGC 770, located off the upper right of this frame. But more distant background galaxies are clearly visible in the cosmic field of view.