(December 18, 2011 at 7:22 pm)Welsh cake Wrote: Which is frightening in that, if it could survive such extreme temperatures, were a comet to collide with us, the Earth-Moon system as we know it would cease to be.
Actually, the millions degree solar Corona in which lovejoy passed is so tenuous that it is practically a vacuum. While each atom in it might zip around with such kinetic energy as to make the thing millions of degrees, there are so few atoms per cubit meter that it could actually impart very little total molecular kinetic energy, ie heat, to any solid objects inside it.
The main source of heating to the comet would have come from the radiation from the sun's surface, not radiative or contact heating from solar corona. So thousands of degrees, not millions.
Also, the core of lovejob is an dirty iceball about 500 meters across. It's a speck next to the 6 mile wide chixalube impactor that killed the donosaurs. As to it's destructive power should it hit the earth moon system, it's enough to ruin the day of anyone living within a few hundred miles, but it won't make any craters visible from the moon.
