He has discovered numerous near-Earth asteroids, including (496816) 1989 UP and (35396) 1997 XF11 (uncredited), which briefly created a stir in the news media when a preliminary orbit calculation indicated the possibility of Earth impact in 2028; further observations led to a more accurate orbit, which disproved the impact.
He has also recovered more than 75 comets starting in 1985 (since comets are subject to non-gravitational forces due to outgassing and solar wind, it is often a challenge to predict their exact position and rediscover them each time they make a new perihelion approach).
He confirmed the discovery of the well known Comet Shoemaker-Levy 9, which impacted Jupiter in July 1994.
Asteroid 3594 Scotti, discovered by Edward Bowell at Anderson Mesa Station in 1983, was named in his honor.
[1] The official naming citation was published by the Minor Planet Center on September 7, 1987 (M.P.C.