Discovered in 2007 by Dutch high-school teacher Hanny van Arkel while participating in Hubble's online Galaxy Zoo project, a green blob known as Hanny's Voorwerp (Hanny's Object in Dutch) is seen to hang below the spiral galaxy IC 2497 located 650 million light years from Earth.
In reality the luminous fog is the result of an interaction with the nearby galaxy. It is believed that a quasar in the galaxy is injecting radiation into a gas cloud, perhaps left behind by a galaxy merger over a billion years ago.
The result is the erie glow of excited oxygen gas lit up across an area roughly the size of our Milky Way galaxy. The dark spot in the blob is actually a 20,000 light-year shadow from an object between the quasar and the gas field. Hubble team members liken the effect to a fly passing in front of a movie projector and casting a shadow on the screen.
The above image was constructed using data taken exposures were taken April 12, 2010 (using the Advanced Camera for Surveys) and April 4, 2010 (using the Wide Field Camera 3). Image Credit: NASA, ESA, W. Keel (University of Alabama), and the Galaxy Zoo Team.
Comments
Using my imagination I can see what appears to be an Angel on the upper right holding a baby in her arms. The dark object seems to held by the top and bottom in the arms of a man on the right side of object/shadow