Comet 67P/Churyumov- Gerasimenko

67P/Churyumov-Gerasimenko - structure of a comet

During this time, it commutes between the orbits of Jupiter and the Earth. However, little is known about it, despite its regular visits to the inner Solar System.
 
Most of the time, its faint image is drowned in a sea of stars, making observations with Earth-based telescopes extremely difficult.

However, during its short-lived excursions to the inner Solar System, the warmth of the Sun causes ices on its surface to evaporate and jets of gas to blast dust grains into the surrounding space.

Unfortunately, although this enveloping ‘coma’ of dust and gas increases 67P/Churyumov-Gerasimenko’s brightness, it also completely hides the comet’s nucleus.
 
 

	The nucleus of Comet Halley

Rosetta's task is to rendezvous with the comet while it still lingers in the cold regions of the Solar System and shows no surface activity.

After releasing a lander onto the dormant nucleus, the orbiter will chase Comet Churyumov-Gerasimenko as it charges headlong towards the inner Solar System at speeds of over to 100 000 kilometres per hour.
 
 

Comet 67P/Churyumov-Gerasimenko   Diameter of nucleus (km) 4 Orbital period (years) 6.6 Minimum distance from Sun (million km) 186 Maximum distance from Sun (million km) 857 Orbital eccentricity 0.6 Orbital inclination (degrees) 7.1 Year of discovery 1969 Discoverers K. Churyumov, University of Kiev, Ukraine   S. Gerasimenko, Institute of Astrophysics, Dushanbe, Tajikistan

 
Over an entire year, as it approaches the Sun, Rosetta will orbit the comet, mapping its surface and studying changes in its activity.

As its ices evaporate, instruments on board the orbiter will study the dust and gas particles which surround the comet and trail behind it as streaming tails, as well as their interaction with the solar wind.
 
 
 
Last update: 5 October 2004

More about...
•	Rosetta (http://www.esa.int/SPECIALS/Rosetta/index.html)
•	Rosetta factsheet (http://www.esa.int/esaSC/SEMJUZS1VED_index_0.html)
•	Rosetta press kit (http://www.esa.int/esaSC/SEMJ09374OD_1_spk.html)
Related articles
•	Comets - an introduction (http://www.esa.int/SPECIALS/Rosetta/SEMMXZ374OD_0.html)
•	History of cometary missions (http://www.esa.int/SPECIALS/Rosetta/SEMCZ3474OD_0.html)
•	Accidental space scientist: An interview with Gerhard Schwehm (http://www.esa.int/SPECIALS/Rosetta/SEMAP5474OD_0.html)
•	Hubble assists Rosetta comet mission (http://www.esa.int/SPECIALS/Rosetta/SEM536474OD_0.html)
•	Why 'Rosetta'? (http://www.esa.int/SPECIALS/Rosetta/ESA26F7708D_0.html)