6 research outputs found
Planet Formation in the Outer Solar System
This paper reviews coagulation models for planet formation in the Kuiper
Belt, emphasizing links to recent observations of our and other solar systems.
At heliocentric distances of 35-50 AU, single annulus and multiannulus
planetesimal accretion calculations produce several 1000 km or larger planets
and many 50-500 km objects on timescales of 10-30 Myr in a Minimum Mass Solar
Nebula. Planets form more rapidly in more massive nebulae. All models yield two
power law cumulative size distributions, N_C propto r^{-q} with q = 3.0-3.5 for
radii larger than 10 km and N_C propto r^{-2.5} for radii less than 1 km. These
size distributions are consistent with observations of Kuiper Belt objects
acquired during the past decade. Once large objects form at 35-50 AU,
gravitational stirring leads to a collisional cascade where 0.1-10 km objects
are ground to dust. The collisional cascade removes 80% to 90% of the initial
mass in the nebula in roughly 1 Gyr. This dust production rate is comparable to
rates inferred for alpha Lyr, beta Pic, and other extrasolar debris disk
systems.Comment: invited review for PASP, March 2002. 33 pages of text and 12 figure