Number 107 (Story #3), December 18, 1992 by Phillip F. Schewe and Ben Stein RADAR IMAGES OF ASTEROIDS keep improving. In monitoring the approach of the asteroid 4179 Toutatis this month, Steven Ostro of JPL hopes to see features as small as 160 m on the 5-km-wide object. Using the Goldstone telescope to transmit (3.5-cm waves) and the VLA radio telescope to receive reflected waves, he expects to make a movie of Toutatis's approach to within 10 lunar distances of Earth. Other recent feats of radar astronomy include the observation of what looks like water ice at Mercury's poles and measurements of Saturn's moon Titan (the echo signal was only 10**-22 watts), suggesting that the moon's rotation period is not precisely the same as its orbital period, as had been thought. (New Scientist, 5 Dec.)