'Potentially hazardous asteroid' bigger than Earth's tallest building will zoom past us next...

Bruce Willis will protect us...I mean Space Operations will destroy it with lasers TSgt David L.

Newton got few equations wrong and the answers for problems like this can be double checked with pen and pencil to extreme accuracy. We have known how to do so since the 17th century,. I would not worry about the math being wrong. this is not only not rocket science it is not even modern science at all. It does take calculus, in fact it is one of the problems calculus was invented, again by Newton, to solve.

And since the data sets h are public it has probably been checked by hundreds of science or astronomy nerds already.