The brightest object ever seen in the universe was detected last week: a gamma ray burst 7.5 billion light years away. For a brief time, the afterglow of the huge explosion could be seen with the unaided eye in the constellation of Boötes. To put 7.5 billion years in perspective: the Earth is 4.6 billion years old, and the entire universe is 13.7 billion years old. This means that, when the light was emitted from this gamma ray burst, the Earth hadn’t even formed!

This image shows the afterglow in X-rays (left) and in ultraviolet light (right). The March 28 Astronomy Picture of the Day has more information.

Posted by Matthew R. Francis under Science News |