ShoemakerLevy

Shoemaker-Levy 9, designated D/1993 F2 and commonly called SL9, was a comet discovered on March 24, 1993 by Carolyn S. Shoemaker, Eugene M. Shoemaker, and David H. Levy using the Palomar Observatory’s 0.46-meter Schmidt telescope. The object had recently passed within Jupiter’s Roche limit, and tidal forces tore it apart into at least 21 fragments. The fragmentation and remaining bound orbit allowed the fragments to be observed as a string of bright spots along an arc in the planet’s vicinity.

Between July 16 and 22, 1994, the fragments collided with Jupiter, producing a series of impacts that generated dark atmospheric scars and towering plumes visible from Earth and by the Hubble Space Telescope. The event marked the first time humanity directly observed a collision between two solar system bodies. The impacts provided valuable data on impact physics, energy release, and Jupiter’s atmospheric response to a major external disturbance, as well as insights into the composition and structure of comets.

Fragments were estimated to range from tens of meters to kilometers in diameter, with a total mass equivalent to a small fraction of a typical comet. The scars on Jupiter faded over weeks to months, but the event left a lasting imprint on planetary science and popular awareness of cometary and impact processes. The name SL9 remains the most common reference to the event, highlighting the collaborative discovery by the Shoemakers and Levy.