Definition
Runaway growth is an accelerated phase in planetary growth during which the growth rate scales with the planet mass (dM/dt ∼ M4/3) such that the largest bodies get larger at a rapid and increasing rate. Runaway growth occurs in cases for which gravitational focusing of small bodies (planetesimals) is very strong. The runaway growth phase is thought to be quite short in most situations and to be stopped when random velocities of the planetesimals are increased to the point where gravitational focusing is stopped and accretion returns to the geometrical regime (where the collision rate is simply proportional to a body’s surface area). However, in situations with very strong damping of planetesimal eccentricities (e.g., via gas drag), runaway growth of planetary embryos can be extended all the way to the point at which a growing planet becomes dynamically isolated from its neighbors by accreting all of the mass in its local neighborhood.
See Also
This is a preview of subscription content, log in via an institution to check access.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Author information
Authors and Affiliations
Corresponding author
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2015 Springer-Verlag Berlin Heidelberg
About this entry
Cite this entry
Raymond, S.N. (2015). Runaway Growth. In: Gargaud, M., et al. Encyclopedia of Astrobiology. Springer, Berlin, Heidelberg. https://doi.org/10.1007/978-3-662-44185-5_1397
Download citation
DOI: https://doi.org/10.1007/978-3-662-44185-5_1397
Published:
Publisher Name: Springer, Berlin, Heidelberg
Print ISBN: 978-3-662-44184-8
Online ISBN: 978-3-662-44185-5
eBook Packages: Physics and AstronomyReference Module Physical and Materials ScienceReference Module Chemistry, Materials and Physics