As a clue to speed, the locals who were on the ground in the fall area in Lesotho for the one I saw heard sonic booms. Estimates are that 3000 meteorites a year fall to earth. Some weigh grams, others tons. Even a gram at the speed of sound would ruin your day... Airlne pilots are in a prime position to see meteorites and I'm interested to know how many of us have seen them close by.