How was Comet Tempel 1 discovered?
Comet Tempel 1 was discovered onApril 3, 1867 by Ernst Wilhelm Leberecht Tempel of Marseilles, France. Because of its periodic nature, 19th-century astronomers kept a close watch on Tempel 1. They observed its return to the inner solar system in 1873 and then again in 1879, but by 1881 gravitational interactions with other objects had changed its orbital period to 6 1/2 years. The comet was then “lost” to observers, according to NASA. Attempts to spot it in 1898 and 1905 failed. In the 1960s, the late comet hunter Brian Marsden studied Tempel 1’s disappearance and predicted it would return in 1967 and 1972. Indeed, the comet was returned on June 8, 1967, then again in January 1972. Tempel 1 now has the official designation comet 9P/Tempel 1. Its orbit has settled into its current 5 1/2-year period and carries the comet between the orbits of Mars and Jupiter.
