Near-Earth object focused on asteroids and short-period comets. CNEOS even restricts its definition of NECs to short-period comets—, 107 such objects have been discovered. , only 20 comets have been observed to pass within of Earth, including 10 which are or have been short-period comets. Two of these comets, Halley's Comet and 73P/Schwassmann–Wachmann, have been observed during multiple close approaches. The closest observed approach was 0.0151 AU (5.88 LD) for Lexell's Comet on July 1, 1770. After an orbit change due to a close approach of Jupiter in 1779, this object is no longer a NEC. The closest approach ever observed for
From the Earth to the Moon stories of Baron Munchausen and Cyrano de Bergerac. In 1889 Verne wrote a second sequel to the novel, "The Purchase of the North Pole", which has the Gun Club members (led by J. T. Maston) plan to use the "Columbiad" to alter the tilt of the earth to enable the mineral wealth of the Arctic region to be put within reach of exploitation. In March 1953, the Gilberton Company published a comic-book adaptation of "From the Earth to the Moon" as issue No. 105 in its Classics Illustrated series. An unidentified scriptwriter combined Verne's "From the Earth to the Moon"