Spaceguard is often referred to as the "Spaceguard Goal." A number of efforts which receive money through NASA are all considered to be working on the "Spaceguard Project." The effect of the impact of Comet Shoemaker–Levy 9 to Jupiter in July 1994 created a greater perception of importance to the detection of near Earth objects. As David Levy stated in an interview "The giggle factor disappeared after Shoemaker-Levy 9." He was referring to the contemporary attitude that extinction level events were so improbable that those advocating for research for detection and possible deflection methods were only paranoid alarmists. The impact of
Comet Shoemaker–Levy 9 carbon disulfide persisted in the atmosphere for at least fourteen months after the collisions, with a considerable amount of ammonia being present in the stratosphere as opposed to its normal location in the troposphere. Counterintuitively, the atmospheric temperature dropped to normal levels much more quickly at the larger impact sites than at the smaller sites: at the larger impact sites, temperatures were elevated over a region wide, but dropped back to normal levels within a week of the impact. At smaller sites, temperatures higher than the surroundings persisted for almost two weeks. Global stratospheric temperatures rose immediately after the impacts,