NGC 2359 (also known as Thor's Helmet) is an emission nebula in the constellation Canis Major. The nebula is approximately 12,000 light-years away and 30 light-years in size. It is also known as Sharpless 2-298, Gum 4 and RCW 5. Image includes IC 468, PGC 149790, PGC 77049, PGC 136794, LBN 1041 and LBN 1040.