"Neurosphere"

Not a galaxy.

"This neurosphere was cultured from an adult mouse brain in a project aiming to determine how new brain cells are born in the adult brain. With nascent neurons (yellow) navigating amongst associated astrocytes (red), it reminds me of a meteorite in the night sky and highlights the mirror relationship between microcosm and macrocosm."

One of the top science and nature photos posted in 2010 in Australian Geographic (credit Dana Bradford).