Although the Hercules A radio galaxy is about 2 billion light years away, it has produced one of the brightest radio sources detectable from Earth. This radio image shows an area over 1,000 light years across. Invisible in the center of this radio image is the giant elliptical galaxy responsible for the jets.
     Hercules A is unusual for a powerful radio galaxy (see PKS 2104-25 for another example). In most radio galaxies the jets are difficult to see and have intense hotspots at their ends, but Hercules A’s jets are quite visible and slowly trail off. The kinks in the jet on the left are from “firehose instability”; the name comes from the way a firehose thrashes as it gushes water full