The odd object was discovered in 2007 by a Dutch schoolteacher participating in Galaxy Zoo—"voorwerp" is Dutch for "object." The online project had public citizens worldwide helping to classify galaxies in the Sloan Digital Sky Survey catalog.

(See related pictures of the "green pea" class of galaxies discovered via Galaxy Zoo.)

Although it's the size of our Milky Way galaxy, Hanny's Voorwerp is not itself a galaxy, but a cloud of gas near the spiral galaxy IC 2497, which lies about 650 million light-years from Earth.

The new Hubble picture—the sharpest yet taken of the brilliant cloud—shows that gas in a