CRAB NEBULA M1

I always wondered why M1 was nicknamed "Crab Nebula", as it does not look at all like that animal. It seems to come from the interpretation by John Pringle Nichol of a drawing by Lord Rosse made in 1842-43 (see second picture). More details are available in Ian Ridpath's excellent article http://www.ianridpath.com/startales/rosse-crab.html