[AJames]

I do disagree with all of you here.

Orion is small compared to the Carina Nebula, which is further away and so much larger. As I've said in more detail elsewhere;

"...covering at least eight times the area of the Great Orion Nebula, M42, and which all southern observers know actually completely reduces the Orion Nebula to a lower grade even though by true apparent magnitude it is slightly less concentrated and as bright. Eta Carinae, and the star that gives it the name, is the brightest, and I dare say also the best nebulae in the sky."

To put it in a true perspective;

"NGC 3372 lies between 1.8kpc to 2.5kpc (6 000 to 8 000 light years) away in the Carina arm of the Milky Way Galaxy. The true estimated size of the nebula is some 400 light years across, some ten to twelve times the area of the Orion Nebula. If it was at the same distance as the Orion Nebula, it would cover the area of Orion's Pot or Venus’s Mirror, and would be incredibly bright – and at best naked-eye covering an area equal to the whole of Orion! Ie. Sunglasses material!"

However, the LMC's Tarantula Nebula is undoubtedly the best nebula of either M42 or NGC 3372. This is the humdinger of them all. In size it is at least four times the area of the Eta Carina Nebulae, and is so bright it is easily seen from a distance of 170 000-odd light-years.