History of radar for various purposes; on the Shuttle Radar Topography Mission, the entire planet was mapped at a 30-m resolution. The Jodrell Bank Observatory, an operation of the University of Manchester in Britain, was originally started by Bernard Lovell to be a radar astronomy facility. It initially used a war-surplus GL-II radar system operating at 71 MHz (4.2 m). The first observations were of ionized trails in the Geminids meteor shower during December 1945. While the facility soon evolved to become the third largest radio observatory in the world, some radar astronomy continued. The largest (250-ft or 76-m in diameter) of their
Eta Aquariids to be a source of meteoric activity. Although this shower is not as spectacular as the Leonids may be and well below the rates of the Perseids or the Geminids, it is not an ordinary event. The Eta Aquariids get their name because their radiant appears to lie in the constellation Aquarius, near one of the constellation's brightest stars, Eta Aquarii. The shower peaks at about a rate of around a meteor per minute, although such rates are rarely seen from northern latitudes due to the low altitude of the radiant. The Eta Aquariids are best viewed in the pre-dawn