Comet Enthusiast

A black-hole jet two billion light years away is carrying the highest electric current ever seen: 1018 amps, equivalent to a trillion bolts of lightning. Philipp Kronberg of the University of Toronto in Canada and colleagues measured the alignment of radio waves around Galaxy 3C303, which has a giant jet of matter shooting from its core. A sudden change in the waves' alignment coinciding with the jet was "an unambiguous signature of a current," says Kronberg.

The team believes that the magnetic fields from a colossal black hole at the galaxy's core are generating the current and driving it through interstellar gases out to a distance of about 150,000 light years.

Image credit: The main power source for a jet emanating from galaxy 3C303 (red dot at centre of image) is a current of about 1018 amps (or one "exa-amp") (Image: Leahy and Perley