67P/Churyumov-Gerasimenko Saturday, June 27, 2009

67P/Churyumov-Gerasimenko
Discovery
Discovered by: Klim Ivanovich Churyumov and
Svetlana Ivanovna Gerasimenko
Discovery date: September 20, 1969
Alternate designations: 1982 VIII; 1982f;
1989 VI; 1988i;
1969 R1; 1969 IV;
1969h; 1975 P1;
1976 VII; 1975i
Orbital characteristics A
Epoch: September 3, 2002 (JD 2452520.5)
Aphelion distance: 5.722 AU
Perihelion distance: 1.2923 AU
Semi-major axis: 3.5072973258 AU
Eccentricity: 0.6315
Orbital period: 6.568 a
Inclination: 7.1205°
Last perihelion: February 28, 2009
Next perihelion: August 13, 2015[1]

67P/Churyumov-Gerasimenko is the designation of a comet with a current orbital period of 6.6 years. It is the destination[2] of the European Space Agency's Rosetta spacecraft mission, launched on March 2, 2004.

Comet physical parameters

Diameter: 4 km

Hubble pictures

3-D Reconstruction of Comet 67P/Churyumov-Gerasimenko's nucleus from Hubble telescope observations

As preparation for the Rosetta mission Hubble Space Telescope pictures taken on March 12, 2003, were closely analyzed. An overall 3-D model was constructed and computer generated images from various view angles are shown in this composite picture.

Discovery

This comet was discovered by Klim Ivanovich Churyumov who examined a photograph exposed for periodic comet 32P/Comas Solá by Svetlana Gerasimenko on September 11, 1969 at the Alma-Ata Astrophysical Institute. He 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, all photographic plates were investigated closely. About a month after the photograph was taken (October 22), it was discovered that the object could not be the assumed comet, because it was about 1.8 degrees off the expected position. Further scrutiny produced a faint picture of Comas Solá at its expected position on the plate, thus proving that the other object was a newly discovered comet.

Orbital history

Churyumov-Gerasimenko has a rather interesting orbital history. Comets are regularly nudged from one orbit to another when they encounter Jupiter or Saturn in close proximity. For this comet it was calculated, that before the year 1840 it was completely unobservable due to its perihelion distance of about 4.0 AU. At this time Jupiter shifted that distance to about 3.0 AU. Later on, in the year 1959, another encounter with Jupiter pushed it to about 1.28 AU, where it is now.

0 comments: