He has discovered numerous asteroids, particularly near-Earth asteroids, and has also recovered more than 60 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. He also discovered the periodic comets P/2000 Y3 Scotti and P/2001 X2 Scotti, which are not yet numbered as they have only been seen at one perihelion.
His research interests include the origin of comets, the dynamical evolution of comets and asteroids, the Near-Earth Asteroids, and the outer solar system.
The asteroid 3594 Scotti is named for him.
He is also an accomplished photographer and painter. The painting below depicts the launch of Apollo 17 from the Moon's surface.