67P/Churyumov–Gerasimenko

From Wikipedia, the free encyclopedia
Jump to: navigation, search
67P/Churyumov–Gerasimenko
Comet 67P Churyumov-Gerasimenko.jpg
Discovery
Discovered by Klim Ivanovych Churyumov
Svetlana Ivanova Gerasimenko
Designations
1969 R1, 1969 IV, 1969h, 1975 P1, 1976 VII, 1975i, 1982 VIII, 1982f, 1989 VI, 1988i[1]
Orbital characteristics[1]
Epoch 2013-Dec-20 (JD 2456646.5)
Aphelion 5.6839 AU (850,300,000 km)
Perihelion 1.2429 AU (185,940,000 km)
3.4634 AU (518,120,000 km)
Eccentricity 0.64113
6.45 yr
Inclination 7.0418°
Physical characteristics
Dimensions 3.5×4 km (2.2×2.5 mi)
Mass 3.14×1012±0.21×1012 kg[2]
Mean density
102±9 kg/m³[2]
0.46 m/s (1.5 ft/s)

Comet Churyumov–Gerasimenko, officially designated 67P/Churyumov–Gerasimenko, is a comet with a current orbital period of 6.45 years[1] and a rotation period of approximately 12.7 hours.[3] The comet will next come to perihelion (closest approach to the Sun) on 13 August 2015.[4][5][6]

It is the destination of the European Space Agency's Rosetta mission, launched on 2 March 2004.[7][8] The Rosetta spacecraft will study the comet and locate a suitable landing site for its Philae lander, scheduled for November 2014.

Discovery[edit]

The comet was discovered by Klim Ivanovych Churyumov, who examined a photograph that had been exposed for periodic comet 32P/Comas Solà by Svetlana Ivanova Gerasimenko on 11 September 1969 at the Alma-Ata Astrophysical Institute. Churyumov found a cometary object near the edge of the plate, but assumed that this was Comas Solá.

After returning to his home institute in Kiev, Churyumov examined all the photographic plates more closely. On 22 October, about a month after the photograph was taken, he discovered that the object could not be Comas Solá, because it was about 1.8 degrees off the expected position. Further scrutiny produced a faint image of Comas Solá at its expected position on the plate, thus proving that the other object was a newly discovered comet.

Observations[edit]

As preparation for the Rosetta mission, Hubble Space Telescope pictures taken on 12 March 2003 were closely analysed. An overall 3D model was constructed and computer-generated images created.[9] On 6 June 2014 water vapor was detected being released from 67P at a rate of roughly 1 litre per second (0.26 USgal/s) when Rosetta was 360,000 km (220,000 mi) from the comet and the comet was 3.9 AU (580,000,000 km) from the Sun.[10][11]

On 14 July 2014, images taken by Rosetta showed that 67P was irregular in shape with two distinct sections, possibly being a contact binary. Other formation scenarios exist, such as 67P having been gravitationally affected by another object, or that significant amounts of ice evaporated and left behind this asymmetric shape. The size was estimated as 3.5×4 kilometres (2.2×2.5 mi).[12][13]

Orbital history[edit]

Comets are regularly nudged from one orbit to another when they encounter Jupiter in close proximity. Before 1959, Churyumov–Gerasimenko's perihelion distance was about 2.7 AU (400,000,000 km). In February 1959, a close encounter with Jupiter[14] moved its perihelion inward to about 1.3 AU (190,000,000 km), where it remains today.[6]

References[edit]

  1. ^ a b c "JPL Small-Body Database Browser: 67P/Churyumov-Gerasimenko". NASA/Jet Propulsion Laboratory. 5 October 2013. Retrieved 21 January 2014. 
  2. ^ a b Maquet, L.; Colas, F.; Jorda, L.; Crovisier, J. (2012). "67P/Churyumov-Gerasimenko mass determination based on a new method for modeling non-gravitiational forces and accelerations". Asteroids, Comets, Meteors. 16-20 May 2012. Niigata, Japan. Lunar and Planetary Institute. Retrieved 11 December 2013. 
  3. ^ "Rosetta's target: comet 67P/Churyumov-Gerasimenko". ESA. 2014-06-14. Retrieved 22 July 2014. 
  4. ^ Yoshida, Seiichi (30 December 2010). "67P/Churyumov-Gerasimenko". Aerith.net. Retrieved 9 February 2012. 
  5. ^ "67P/Churyumov-Gerasimenko". Minor Planet Center. Retrieved 17 June 2014. 
  6. ^ a b Kinoshita, Kazuo (7 May 2009). "67P/Churyumov-Gerasimenko". Comet Orbit. Retrieved 25 April 2009. 
  7. ^ Krolikowska, Malgorzata (2003). "67P/Churyumov–Gerasimenko – potential target for the Rosetta mission". Acta Astronomica 53: 195–209. arXiv:astro-ph/0309130. Bibcode:2003AcA....53..195K. 
  8. ^ Agle, D. C.; Cook, Jia-Rui; Brown, Dwayne; Bauer, Markus (17 January 2014). "Rosetta: To Chase a Comet". NASA. Release 2014-015. Retrieved 18 January 2014. 
  9. ^ Buckley, Michael; Villard, Ray; Christensen, Lars (5 September 2003). "Hubble Assists Rosetta Comet Mission". HubbleSite.org. 
  10. ^ "First Detection of Water from 67P/C-G". European Space Agency. 23 June 2014. Retrieved 23 June 2014.  Sungrazer Comets
  11. ^ Agle, D. C.; Brown, Dwayne; Bauer, Markus (30 June 2014). "Rosetta's Comet Target 'Releases' Plentiful Water". NASA. Retrieved 30 June 2014. 
  12. ^ "The twofold comet: Comet 67P/Churyumov-Gerasimenko". Astronomy.com. 17 July 2014. Retrieved 18 July 2014. 
  13. ^ Temming, Maria (17 July 2014). "Rosetta's Comet has a Split Personality". Sky & Telescope. Retrieved 18 July 2014. 
  14. ^ "JPL Close-Approach Data: 67P/Churyumov-Gerasimenko". NASA/Jet Propulsion Laboratory. 29 June 2010. Retrieved 9 February 2012. 

External links[edit]

Further reading[edit]


Periodic comets (by number)
Previous
66P/du Toit
67P/Churyumov–Gerasimenko Next
68P/Klemola