OK, aside from the impressive sight of the very sudden amazing brightening of Comet Holmes, I was observing it last night and it occured to me that its what, 165 million miles away? In the eyepiece its angular size is way, way WAY bigger than the planet Mars. Now I'm thinking that, as solar system objects go, the core of this comet is not all that large, a few tens of kilometers maybe (I have not seen any write-ups about that). So it occurs to me to see if anyone has calculated the explosive power it required to blow enough dust and gas out to a diameter of what has to be 6 or 8 times the diameter of Mars, enough dust and gas to glow brighter than mag 3! It is mind boggling to me that a cold hunk of dust and ice moving away from the sun, that was mag 17 and did not really do much of anything during its travel close to the sun, and now as it exits halfway to Jupiter it explodes with enough force to through out the volume of dust needed to create the size and brightness. That's not just a couple pounds of evaporating ice! We're talking some serious blast power are we not? Anyone besides me wondering where that power came from?