Comet 67P/Churyumov-Gerasimenko (67P/C-G) is a short-period comet with an orbital period of approximately 6.4 years. Discovered in 1969 by Soviet astronomers Klim Churyumov and Svetlana Gerasimenko, this comet has become one of the most studied in history due to the ambitious mission undertaken by the European Space Agency (ESA).
ESA's Rosetta Mission
The Rosetta Mission, launched by ESA on March 2, 2004, was designed to perform detailed studies of comet 67P/C-G. Here are some key points about the mission:
- Launch: Rosetta was launched on an Ariane 5 rocket from Kourou, French Guiana.
- Journey: The spacecraft took a decade-long journey through the Solar System, including gravity-assist flybys of Earth and Mars to gain the necessary velocity to reach the comet.
- Arrival: Rosetta rendezvoused with 67P/C-G on August 6, 2014, becoming the first spacecraft to orbit a comet.
- Philae Lander: On November 12, 2014, the Rosetta mission deployed the Philae lander, which became the first spacecraft to land on a comet's surface.
- Scientific Investigations: Rosetta carried 11 scientific instruments to study the comet's nucleus, dust, gas coma, and its interaction with solar wind. Philae had nine instruments to conduct in-situ studies.
- End of Mission: After two years of detailed observation, Rosetta's mission ended on September 30, 2016, when the spacecraft was intentionally crash-landed onto the comet's surface to prevent potential contamination of other celestial bodies.
Scientific Findings
The mission provided invaluable data:
- Comet's Shape: 67P/C-G has a distinctive 'rubber duck' shape, consisting of two lobes connected by a narrower neck, likely due to a low-speed collision of two separate bodies.
- Composition: Studies confirmed the presence of water, carbon dioxide, ammonia, methane, and complex organic molecules, supporting the theory that comets could have delivered key ingredients for life to Earth.
- Activity: The comet's activity was monitored, showing how its nucleus sublimates as it approaches the sun, releasing gas and dust to form its coma and tail.
- Nucleus Properties: The surface of the comet was found to be more rugged than expected, with pits, cliffs, and boulders, and its nucleus was determined to have a density suggesting it is a rubble pile rather than a solid body.
Legacy and Impact
The Rosetta mission has left a lasting impact:
- It has provided insights into the origins of our Solar System, the processes of comet formation, and the potential role of comets in delivering water and organic compounds to Earth.
- The mission demonstrated the feasibility of long-duration space missions and the study of small bodies in the Solar System.
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