Allow me to explain why i got so damn excited about the Mars landing. i realized that i needed a good way to explain this to my wife, who didn't quite understand why i was screaming and dancing.
Tossing a wad of paper into the bin beneath your desk is easy. Chances are you can do it mindlessly, and while it may have been a challenge when you were, say, six, you've managed to successfully perform that task more often than than not. Perhaps you've even gotten to the point where you can land the wad in the center of the bin from across the room/cube, possibly to the imagined cheer of the crowd.
A bit of a challenge, but something that you feel reasonably comfortable doing, right. Ok, let's up the challenges a bit. Tape a cell of skin to a snail, tie an ultra fine needle to the bottom of a balloon and with the needle about 2 feet away from the cell, drop it so it hits the cell of skin. On the first try. Congrats! You now understand how hard it was to hit the moon. The needle is way bigger, of course, and the balloon prevents you from breaking relative light speed to hit the mark, but that's about right.
So, how hard was it to hit Mars? Try the same experiment, only this time, drop the balloon needle from the Observation Deck of the old Sears Tower in Chicago.
No, i'm not kidding. Mars was that far away to scale. Of course, to be proper about this, you'd actually drop the balloon while you were moving as well.
As an added bonus to help understand, let's say you've got a little car made out of Lego. We'll need to scale things up, obviously, but you'd need to drop that car, from the International Space Station and have it land at the base of the Old Sears Tower without so much as a bounce.
Mind you, none of that includes the fact that the real deal weight as much as a Mini Cooper, was loaded with experiments and we had absolutely zero control over it during the most dangerous part.
Yeah, that's why i was cheering and so damn impressed.
(And now i expect to have my math corrected by others who'll point out that i goofed on my estimates, but that's fine. It's how we learn.)