Comet Shoemaker–Levy 9 by the comet fragments punching through the upper atmosphere. Spectroscopic studies revealed absorption lines in the Jovian spectrum due to diatomic sulfur (S) and carbon disulfide (CS), the first detection of either in Jupiter, and only the second detection of S in any astronomical object. Other molecules detected included ammonia (NH) and hydrogen sulfide (HS). The amount of sulfur implied by the quantities of these compounds was much greater than the amount that would be expected in a small cometary nucleus, showing that material from within Jupiter was being revealed. Oxygen-bearing molecules such as sulfur dioxide were not detected, to
Naming of comets the past, when multiple comets were discovered by the same individual, group of individuals, or team, the comets' names were distinguished by adding a numeral to the discoverers' names (but only for periodic comets); thus Comets Shoemaker–Levy 1 to 9 (discovered by Carolyn Shoemaker, Eugene Shoemaker & David Levy). Today, the large numbers of comets discovered by some instruments makes this system impractical, and no attempt is made to ensure that each comet is given a unique name. Instead, the comets' systematic designations are used to avoid confusion. Until 1994, comets were first given a provisional designation consisting of the