Astronomers had theorized that the ring was primordial gas in the process of forming a galaxy.

The GALEX satellite detected ultraviolet emissions that astronomers at Johns Hopkins University and the Carnegie Institution for Science interpret to indicate star creation in newly forming dwarf galaxies in a 19 February 2009 Nature paper.

[5] In 2010, it was suggested that the gas was not primordial, but instead the result of a galactic collision between the two galaxies with which the ring is closely associated.

[6] It has been suggested that 1.2 billion years ago, NGC 3384 collided with M96, at the heart of the Leo Group, expelling a galaxy's worth of gas into intergalactic space.

This gas gathered into a vast set of clouds, the Leo Ring.