|Discovered by||Alphonse Borrelly|
|Discovery date||December 28, 1904|
|1905 II; 1911 VIII; 1918 IV;|
1925 VIII; 1932 IV; 1953 IV;
1960 V; 1967 VIII; 1974 VII;
1981 IV; 1987 XXXIII; 1994 XXX
|Epoch September 8, 2001 (JD 2452160.5)|
(February 1, 2022)
|Earth MOID||0.37 AU (55 million km)|
Comet Borrelly // or Borrelly's Comet (official designation: 19P/Borrelly) is a periodic comet, which was visited by the spacecraft Deep Space 1 in 2001. The comet last came to perihelion (closest approach to the Sun) on May 28, 2015 and will next come to perihelion on February 1, 2022. The comet's nucleus, seen in the adjacent image, is particularly notable for being shaped like a bowling pin.
Deep Space 1 flyby
On September 21, 2001 the spacecraft Deep Space 1, which was launched to test new equipment in space, performed a flyby of Borrelly. It was steered toward the comet during the extended mission of the craft, and presented an unexpected bonus for the mission scientists. Despite the failure of a system that helped determine its orientation, Deep Space 1 managed to send back to Earth what were, at the time, the best images and other science data from a comet.
- Seiichi Yoshida (2014-08-10). "19P/Borrelly". Seiichi Yoshida's Comet Catalog. Retrieved 2014-10-29.
- Weaver, H. A.; Stern, S.A.; Parker, J. Wm. (2003). "Hubble Space Telescope STIS Observations of Comet 19P/BORRELLY during the Deep Space 1 Encounter". The American Astronomical Society. 126 (1): 444–451. Bibcode:2003AJ....126..444W. doi:10.1086/375752. Retrieved 2008-12-16.
- "19P/Borrelly: Facts & Figures". Archived from the original on 2014-08-09. Retrieved 2014-08-08.
- Using the volume of an ellipsoid of 8x4x4km * a rubble pile density of 0.3 g/cm³ yields a mass (m=d*v) of 2.0E+13 kg.
- D. T. Britt; G. J. Consol-magno SJ; W. J. Merline (2006). "Small Body Density and Porosity: New Data, New Insights" (PDF). Lunar and Planetary Science XXXVII. Archived (PDF) from the original on 17 December 2008. Retrieved 2008-12-16.
- Robert Roy Britt (2001-11-29). "Comet Borrelly Puzzle: Darkest Object in the Solar System". Space.com. Archived from the original on 22 January 2009. Retrieved 2008-12-16.
- 19P – Gary W. Kronk's Cometography
- Elements and Ephemeris for 19P/Borrelly – Minor Planet Center