A long-period comet discovered independently in 1983 by the IRAS infrared satellite, Genichi Araki and George Alcock. At its closest to Earth, on 11 May, it was just 0.03 AU (4.6 million km) away—the closest approach of any comet since Lexell's Comet of 1770. At this time it was a large diffuse object of magnitude 2, moving rapidly across the sky