Title:[1043] Classic view of Comet Halley Caption:This black-and-white image of Comet Halley might be considered a classic view of most people's idea of what a comet looks like. Photograph taken at Cerro Tololo on the Schmidt camera, March 6, 1986. Copyright: Credit:National Optical Astronomy Observatories

Title:[1042] Comet Halley Caption:Comet Halley, seen as a spherical image, races across a background of star trails toward its nearest approach to Earth, at 4:44 pm, Eastern time, 10 April 1986. This Cerro Tololo photograph was taken in a one-hour exposure by Gabriel Martin, using the 24/36-inch Curtis Schmidt telescope. Copyright: Credit:National Optical Astronomy Observatories

Title:[1185] Comet Halley Caption:Comet Halley takes the scenic route, sweeping past a glowing cloud of interstellar dust and gases in this photograph from a National Optical Astronomy Observatories (NOAO) telescope in northern Chile. Halley is the bright, star-like object at right center, caught as it swept past the nebula NGC 2174 in the constellation Orion. The comet is climbing from left to right at an angle of about ten degrees. The 15-minute exposure was made by Arturo Gomez early (8:25 UT) on the morning of October 11, 1985, at NOAO's Cerro Tololo Inter-American Observatory. Gomez used an unfiltered, blue-sensitive plate on the Curtis-Schmidt telescope. Copyright: Credit:National Optical Astronomy Observatories

Title:[0433] Comet Halley, 1986 Caption:Comet Halley, 1986 Copyright:(c) 1986 ROE/AAT Board Credit:

Title:[1044] Comet Halley in 1910 Caption:Comet Halley in 1910. This computer-reconstructed image was processed at Kitt Peak from an original black-and-white plate taken in 1910 at Lowell-Observatory, Flagstaff, Arizona. The false colors indicate varying levels of brightness. Type I ion tail is visible above Type II dust tail. Copyright: Credit:National Optical Astronomy Observatories

Title:[0846] Comet Halley on May 13, 1910 Caption:Lowell Observatory wide angle photograph of Comet Halley on May 13, 1910, showing the comet, a meteor superimposed on the tail, a bright Venus, and the streaked lights of Flagstaff. Copyright: Credit:National Optical Astronomy Observatories

Title:[1041] Comet Halley passes the Pleiades Caption:Comet Halley passes the Pleiades star cluster in this color photo taken early on November 16, 1985. Cerro Tololo Inter-American Observatory, Curtis-Schmidt telescope 15-minute exposure, by Marcelo Bass. Copyright: Credit:National Optical Astronomy Observatories

Title:[0847] Photograph of Comet Halley Caption:Lowell Observatory photograph of Comet Halley computer-processed and false color added by M. J. S. Belton. Kitt Peak National Observatory. Copyright: Credit:National Optical Astronomy Observatories

Title:[0848] The first view of Comet Halley since 1911 Caption:The first view of Comet Halley since 1911 shows only the starlike nucleus on October 16, 1982. Copyright: Credit:National Optical Astronomy Observatories

Title:[0273] The tails of Comet Halley on 12 March 1986 Caption:To those prepared to leave their brightly-lit suburbs and seek dark skies, Comet Halley was there to be enjoyed in the first months of 1986, especially in the southern hemisphere. The warming action of sunlight on the tiny nucleus of the comet evaporates volatile materials from its surface, which expand rapidly in the vacuum of space, producing the large coma. Solar radiation pressure sweeps back this tenuous cloud into the typical comet shape. Emerging from the coma, two distinct tails can be seen. The blue one is primarily due to water vapor, dissociated by ultraviolet sunlight, fluorescing in the blue color of the cyanogen radical, while the faint yellow streak is sunlight reflected from dust particles liberated from the nucleus along with the volatile materials. Copyright:(c) 1986 Royal Observatory Edinburgh Credit:D. F. Malin