NASA's Hubble Telescope has captured an unusual, ghostly green blob of gas that appears to float near a neighboring spiral galaxy.
The strange blob, whose bright green color is from glowing oxygen, is said to be producing new stars in remote areas of the universe where stars are not expected to form.
The blob was first discovered by Hanny van Arkel, an elementary school teacher, as part of a worldwide Galaxy Zoo project. Now, the Hubble snap provided a clear picture and better explanation for what is happening around the blob, which is named as Hanny's Voorwerp (means Hanny's Object in Dutch).
The green blob is the only visible part of a 300,000-light-year-long streamer of gas stretching around the galaxy, called IC 2947.
The greenish Voorwerp is visible because a beam of light from the galaxy's core illuminated it. This beam came from a quasar -- a bright, energetic object powered by a black hole -- and the quasar may have turned off about 200,000 years ago.
Scientists say the Voorwerp, which is the size of our Milky Way galaxy, may have been created from an interaction between IC 2947 and another galaxy about a billion years ago.
The Hubble image shows that IC 2947 has been disturbed, with complex dust patches, warped spiral arms, and regions of star formation around its core, suggesting the aftermath of a galaxy merger.