Tony’s Posterous

Image of the Day: Einstein's Cross

The Einstein Cross is a gravitationally lensed quasar that is quadruply imaged, hence its name, Einstein Cross, forming a nearly perfect cross, with the lensing galaxy at its center. The quasar is located about 8 billion light years from Earth, while the lensing galaxy is located at a distance of 400 million light years. Many scientists believe quasars are powered by giant black holes feeding on nearby gas. Gas trapped in the black hole's powerful gravity is compressed and heated to millions of degrees, giving off intense light and/or radio energy. Most quasars lurk in the outer reaches of the cosmos, over a billion light years away, and are therefore distant enough to appear stationary to us.