Asteroid or comet | | | | | |
| | | | | | |  Automatic translation | | | | | | Comet Hartley 2 | | Updated: 06/11/2010 | | category : asteroids - comets |  | | | | | What is the explanation for the strange resemblance between the comet Hartley 2 in 2010 and explored the asteroid Itokawa visited in 2005?
The Japanese probe Hayabusa, Itokawa showed us a surface that alternates between smooth areas and rocky areas. Epoxi probe as it moved closer to the comet 103P/Hartley 2, we also showed areas of smooth and rocky areas.
This strange resemblance between the two bodies reinforces recent numerical simulations showing that old comets may have migrated into the asteroid belt during the Late Heavy Bombardment (Late Heavy Bombardment or LHB, in English).
Itokawa could have been a comet before the disruption occurred in the solar system there are 4 billion years. On November 4, 2010, the former U.S. probe Deep Impact, renamed Epoxi for the occasion, flew over the nucleus of comet Hartley 2 at a distance of 700 kilometers.
Comet 103P/Hartley 2 is a young and active comet specialists studying active regions that release the gas and dust behind the hair. | | The images of the comet Hartley 2 show clearly its shape into a pickle and various jets of gas and dust. | Hartley 2 | | | | Size | | 2,2 km | | Rotation | | 18 H | | Discovered by | | Malcolm Hartley | | date of discovery | | 15/03/1986 | | Aphelion | | 5,87 ua | | Perihelion | | 1,05 ua | | Period orbital | | 6,46 years | | perihelion passage 1985 | | ~05/06/1985 | | perihelion passage 1991 | | ~11/09/1991 | | perihelion passage 1997 | | ~22/12/1997 | | perihelion passage 2004 | | 17/05/2004 | | perihelion passage 2010 | | 28/10/2010 |
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* View 103P/Hartley core 2 made by the probe as it moved Epoxi closer to the comet 4/11/2010. © Nasa. | | | | | | | | The asteroid Itokawa | | | | | | | | | | Itokawa could have been a comet before the disruption occurred in the solar system there are 4 billion years.
Numerous small rocky bodies called asteroids are present in the solar system, a significant portion of them circulate in a ring between the orbits of Mars and Jupiter between 2 and 4 UA (symbole : UA) The mean distance Earth to the Sun. An AU is 149,597,871 km. It is a unit often used for distances in the solar system, or the distance between two stars in a dual system. , in the asteroid belt.
This belt marks the boundary between the terrestrial planets and gas giants.
An asteroid is a celestial object is not observable to the naked eye because of its small size, which varies from a few tens of meters to several hundreds of kilometers in diameter and is part of our solar system.
The near-Earth asteroids, or ACE, English Earth-Crossing Asteroids are celestial objects that orbit the Sun and which periodically passes near the orbit of the Earth.
They are classified into three broad families. The Aten, which have a semi-major axis of less than one astronomical unit.
| | The Apollo, which cross the orbit of the Earth with a period exceeding one year. The Amor, which border the outer orbit of the Earth. The asteroid 25143 Itokawa is like Apollo. | Itokawa | | | | Dimensions | | 607 x 287 x 264 m | | Mass | | 3 5*10e10 kg | | Rotation | | 18 H | | Aphelion | | 1.695 UA | | Perihelion | | 0.953 UA | | Period of revolution | | 556,38 days |
* image taken by the Japanese probe Hayabusa in 2005. The probe landed on the asteroid 19 November 2005 and brought back rock samples (1500 grains of dust) in 2010. | | 
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| Astronomy - November 4, 2010 |
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