19P/Borrelly
Periodic comet visited by Deep Space 1 in 2001.
19P/Borrelly, also known as Comet Borrelly or Borrelly's Comet, is a periodic comet with an orbital period of 6.85 years. It was discovered in 1904 and later became notable as the target of a flyby by the Deep Space 1 spacecraft in 2001, which returned the highest-resolution images of a comet nucleus up to that time.
Quick Facts
- Pronounced
- b · Q · ' · r · E · l · i
- Discoverer
- Alphonse Borrelly
- Discovery Site
- Marseille, France
- Discovery Date
- 28 December 1904
- Mpc Name
- P/1904 Y2, P/1911 S1
- Designations
- 1905 II, 1911 VIII · 1918 IV, 1925 VIII · 1932 IV, 1953 IV, 1960 V · 1967 VIII, 1974 VII · 1981 IV, 1987 XXXIII · 1994 XXX
- Orbit Ref
- jpldata
- Epoch
- 9 August 2022 (JD 2459800.5)
- Perihelion
- 1.306 AU
- Aphelion
- 5.90 AU
- Semimajor
- 3.61 AU
- Eccentricity
- 0.6377
Facts from the source article.
Lore & Background
Comet 19P/Borrelly was discovered by Alphonse Borrelly on 28 December 1904 during a routine search for comets at Marseille, France. It orbits the Sun with a period of 6.85 years, last reaching perihelion on 1 February 2022 and next due on 11 December 2028.
The comet was visited by the Deep Space 1 spacecraft on 21 September 2001. Deep Space 1 had been launched to test new equipment in space, and the flyby occurred during its extended mission, presenting an unexpected bonus for mission scientists. Despite the failure of a system that helped determine its orientation, the spacecraft managed to send back images and other science data from a distance of 3400 kilometers. At 45 meters per pixel, these were the best images and highest-resolution view ever seen of a comet up until that time.
Reader's Guide
The flyby of 19P/Borrelly by Deep Space 1 marked a significant milestone in cometary science. The spacecraft, originally designed to test new technologies, was redirected toward the comet during its extended mission, and the encounter provided an unplanned but valuable opportunity for study. Despite the failure of an orientation system, Deep Space 1 successfully returned images and data from 3400 kilometers away, achieving a resolution of 45 meters per pixel—the highest-resolution view of a comet nucleus ever obtained at that point. These observations gave scientists an unprecedented look at the comet's nucleus and contributed to the understanding of cometary structure and composition. The mission demonstrated that even a technology-testing spacecraft could yield important scientific returns when directed toward a suitable target. The data from the flyby remain a reference point for later comet missions.
Did You Know?
- Deep Space 1 flew by the comet on 21 September 2001 from a distance of 3400 kilometers.
- The images returned had a resolution of 45 meters per pixel, the highest of any comet up to that time.
- The flyby was an unexpected bonus during Deep Space 1's extended mission.
More in Named Comets, Part 5 1-24
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