Astronomy Picture of the Day . Comet Halleys Nucleus: An Orbiting Iceberg . ... In 1986, however, the European spacecraft Giotto became one of the first group of spacecraft ever to encounter and photograph the nucleus of a comet, passing and imaging Halley's nucleus as it approached the sun. ... This debris shed from Halley's nucleus eventually disperses into an orbiting trail responsible for the Orionids meteor shower , in October of every year, and the Eta Aquariids meteor shower every May. ...