Ya - no problem Spanker. Certain relative physics situations, such as velocity can sometimes be hard to grasp unless they are put in everyday terms. 40K mph is retarded fast, so you have to show it in terms of distance covered.

The boys at NASA say that all of the "doomsday asteroid" movies and shows get it wrong by showing it approaching earth while everyone on the ground just stares at it hurling towards us. It doesn't work that way. You don't get to "see" anything. They are black in a black sky until they hit the atmosphere. The leading edge of a true planet killer (~5+ miles in size) gets so hot when it hits the upper atmosphere that the heat vaporizes most everything on that side of the planet BEFORE the actual impact. It’s a brilliant white light for a mere millisecond and it’s all over.

Sleep tight.