Has he lost his marbles?

Actually, no, he knows exactly where they went - and for a good reason:

Shooting Marbles At 16,000 Miles Per Hour:

NASA scientist Bill Cooke is shooting marbles and he's playing "keepsies." The prize won't be another player's marbles, but knowledge that will help keep astronauts safe when America returns to the Moon in the next decade. Cooke is firing quarter-inch diameter clear shooters - Pyrex glass, to be exact - at soil rather than at other marbles. And he has to use a new one on each round because every 16,000 mph (7 km/s) shot destroys his shooter.