Thirty years ago this month, in July 1994, comet Shoemaker–Levy 9 collided with the gas giant Jupiter. The event, the impact of a comet with a planet, caused great excitement worldwide because it was the first predicted collision between two bodies in the Solar System and the first to be monitored through Earth- and space-based telescopes. It would provide astronomers with the chance to study impacts on a planet for the first time and prepare for potential collision events on Earth in the future.
The comet was discovered more than a year before the collision, on a partly cloudy spring evening in March 1993 at the Palomar Observatory in Southern California. Comet and asteroid hunters David H Levy and Carolyn and Gene Shoemaker had gathered at the observatory to continue their search for small bodies that could potentially pose a threat to Earth. During a window of clear sky on 24 March, Levy pointed an 18-inch Schmidt telescope loaded with Kodak film at Jupiter and started taking photographs over a period of eight minutes. The
