fr en es pt
Contact the author rss astronoo

Asteroid or comet

Comet Hartley 2

 Automatic translation  Automatic translation Updated June 01, 2013

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
 hartley 2 flew by the Deep Impact 04/11/2010

Image: View 103P/Hartley core 2 made by the probe as it moved Epoxi closer to the comet 4/11/2010. © Nasa.

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.

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: 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.

 asteroid Itokawa

1997 © − Astronomy, Astrophysics, Evolution and Ecology.
"The data available on this site may be used provided that the source is duly acknowledged."