Green Blob Of Gas the Size of the Milky Way Galaxy

Green blob of gas
Courtesy of Hubble/NASA

Hanny's Voorwerp, a mysterious, glowing green blob the size of our Milky Way galaxy, was first observed by a Dutch teacher Hanny van Arkel.

Radio studies have revealed that Hanny's Voorwerp is is part of a long, twisting rope of gas, or tidal tail, about 300,000 light-years long that wraps around the galaxy. Astronomers believe that it was formed in a galactic merger. 

Hanny's Voorwerp contains a star birthing region that faces the spiral galaxy IC 2497, located about 650 million light-years from Earth. The new Hubble images reveal that the galaxy's gas is interacting with a small region of Hanny's Voorwerp, which is collapsing and forming stars. The youngest stars are a couple of million years old.