Movshovitz tossed the square landers onto a computer-simulated
asteroid. The rubbery side bounced, as designed. But too many
landers came to rest wrong-side down. They developed a new
design -- an egg-shaped lander weighted on the bottom, just like
the Weebles that Asphaug played with as a kid. "I was fascinated
by Weebles," Asphaug said. The toys, first produced in 1971,
could be knocked in any direction but would still come to rest
right-side up. Asphaug bet Movshovitz that the wobbly pods would
work better than the previous "sandwich" lander, even in
microgravity. Movshovitz made the lower half of the pod nine
times heavier than the upper half. In his simulation, the lower
half was colored red, the upper half green. The landers,
descending to the simulated surface, look like tomatoes falling
from heaven. Every roly-poly lander popped right up, even one
that had landed on its head. Asphaug won the bet. Movshovitz
also is using video game physics to study how asteroids break
apart in a planet's orbit. The ph