Astronomy Picture of the Week – Unusual Spiral Galaxy M66

This is a photo of an unusual spiral galaxy called M66, taken by the Hubble Telescope. It lies about 35 million light years from Earth and it spans 100,000 light years.

At a first glance, this galaxy looks familiar. Why? Well, because it is similar to our own galaxy, the Milky Way. Both galaxies are spirals. However, what’s really unusual about this one is that it is asymmetric.

Usually the force of gravity of a mega black hole (or group of mega black holes) attracts all the stars and interstellar gas in a symmetric pattern. If the mega black hole is not originally in the center of a galaxy it makes itself the center by moving all the stars and gas accordingly. However, here the galaxy’s core where the mega black hole(s) is(are) located is not at the center of the galaxy. This is most likely caused by previous close interactions as well as the tidal gravitational pulls of it’s galactic neighbors such as M65 and NGC 3628.

Unusual Spiral Galaxy M66 by Hubble

Image Credits: NASA and Hubble Space Telescope.