Unlike most comets, most of their orbits are close to Jupiter or farther away from the sun track Near circular, and in Asteroid belt It is difficult to distinguish the orbital characteristics from many standard asteroids. Even if there are some Short period comet The semi major axis of the orbit of the main belt comet is within the orbit of Jupiter, which is still different from that of the main belt comet, because the Eccentricity And orbital inclination are similar to asteroids in the main belt. The orbits of the three main belt comets initially known are inside the outer edge of the main belt [1] 。 I don't know from Outer solar system How can other comets, like other comets, change their orbital parameters under the weak gravitational disturbance of planets and become the main belt comets with low eccentricity and orbits like typical asteroids. Therefore, he was supposed to be different from other comets. The main belt comet was formed near the present position of the inner solar system. It was only an ice asteroid, and there were many asteroids with ice. Some main belt comets will appear tails only when they are near perihelion in orbit. The activities of 133P/Elster Pisaro are periodic, and were observed at the last three perihelion approaches. During the 5-6 year orbital period, the activity lasted for one month or several months, and it is speculated that the ice layer no longer covered the asteroid due to the micro impact in the past 100 to 1000 years. These impacts are suspected to have caused the surface to be excavated into pits and exposed volatile substances to solar radiation.
In January 2010, when P/2010 A2 (LINEAR) was discovered, it was initially given the comet model and considered to be a member of this group, but now it is believed that P/2010 A2 is the debris left after the collision between asteroids and asteroids. The observation of 596 Scheila also pointed out that a large amount of dust was raised by the impact of another asteroid with a diameter of about 3.5 meters.
Since the deuterium hydrogen ratio of the water on the Earth is far lower than that of the traditional comet, which is considered as the main source, it is assumed that the main belt comet may be the source of the water on the Earth.
The term 'main belt comet' is an expanded classification based on the orbit and its location, which does not mean that these objects are comets, or the substances around the core are volatile substances like comets.
Members classified in this category include:
full name | Hsieh | Juvit | | | Perihelion date |
|---|
133P/Elster Pizarro | Y | Y | three point one five | two point six four | February 8, 2013 |
176P/Linnaeus | Y | Y | three point one nine | two point five seven | July 2, 2011 |
238P/Reed (P/2005 U1) | Y | Y | three point one six | two point three six | March 0, 2011 |
P/2008 R1 (Garradd) | Y | Y | two point seven two | one point seven nine | January 25, 2013 |
| Y | Y | two point two nine | two | December 4, 2009 |
P/2010 R2 (La Sagra) | Y | Y | three point zero nine | two point six two | June 25, 2010 |
596 Scheila | Y | Y | two point nine two | two point four four | May 19, 2012 |
(300163) 2006 VW139 | Y | Y | three point zero five | two point four four | July 18, 2011 |
P/2012 F5 (Gibbs) | N | Y | three | two point eight eight | March 26, 2010 |
P/2012 T1 (PANSTARRS) | Y | Y | three point one five | two point four one | September 11, 2012 |
