Asteroid orbital distribution

Bottke et al (2005a,b) found that the current asteroid size distribution arose early in its history, when the total mass and collision rate were much higher than today. Once the Asteroid Belt was dynamically depleted and reached roughly its current mass (via the processes described above), there was little further evolution of the size distribution, and hence it has been referred to as a fossil size distribution. Collisions still occur, albeit at a reduced rate, and large collisions lead to the formation of asteroid families, which are groups of asteroids that are clustered in orbital-element (a, e, i) space. Numerous asteroid families can be seen in Fig. 10.6. 

Kirkwood gap Any of several spaces in the distribution of asteroids in the main belt that correspond to locations of orbital resonance with Jupiter. Consequently any asteroids found there have long ago b n perturbed by Jupiter s enormous gravitational influence into more eccentric orbits. The gaps were discovered by the American astronomer Daniel Kirkwood (1814-95). 

Following another path of bifurcation in the hierarchy of complexity, one may now proceed from matter particles to the Earth and the Solar System, the Milky Way (that contains about as many stars - a hundred billion - as there are cells in a human brain), and the whole Universe. This latter involves regular stars (some with planets, satellites, asteroids and comets), neutron stars and dust clouds, which make up galaxies and clusters, and such strange objects as quasars, pulsars or black holes. The regularity of the distribution of planets in our solar system has inspired to Greek philosophers a correspondence with the musical scale that Kepler (who set up the laws of planetary motion) called the "harmony of the spheres". By transposing the orbital velocities of... 

The mean orbits of all planets, including Ceres, the largest asteroid, are correctly predicted [13] by the relative distances from the spiral center. With the orbital radii expressed as rational fractions, a quantized distribution of major planets, as numbered, is revealed. On this scale the orbit of Ceres measures r and those of the inner planets are rational fractions of the golden ratio. The same pattern was shown to repeat itself for the orbital motion of planetary moons and rings. 

The group of small solar system bodies, SSSBs, comprises asteroids, comets and smaller objects. The most part of the smaller objects is concentrated in belts. The orbits of the objects of the Main Asteroid Belt between Mars and Jupiter and the Kuiper Belt outside the orbit of Neptune are concentrated near the ecliptic (plane of the solar system), the objects of the Oort cloud are distributed spherically and extend as far as to 50 000 AU from the Sun. 

For the JIMO mission, the primary micrometeoroid concerns would occur at the asteroid belt and at Jupiter. The moons of Callisto, Europa, and Ganymede would be the primary mission objective for JIMO, Reference 10- 8. The moons orbit at 26.33, 9.40. and 14.97 Jovian radii, respectively, which are beyond the range of the rings. Micrometeoroids velocities of 60 - 70 km/sec near Jupiter are possible, but velocities between 14 km/sec and 22 km/sec are more likely per Table 10-7. Table 10-6 and Figure 10-16 shows typical micrometeoroid velocities and flux distributions between Earth Orbit (1 AU) and Jupiter (5.2 AU). 

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