Comet Halley's Nucleus . ... Credit Copyright: Halley Multicolour Camera Team, Giotto , ESA Copyright : MPAE Explanation: Here is what a comet nucleus really looks like. For all active comets except Halley , it was only possible to see the surrounding opaque gas cloud called the coma. During Comet Halley 's most recent pass through the inner Solar System in 1986, however, spacecraft Giotto was able to go right up to the comet and photograph its nucleus. ... NASA Official: Jay Norris. ...