PRODUCTION OF NEAR-EARTH ASTEROIDS ON RETROGRADE ORBITS
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia (Canada)
- Department of Physics, Engineering Physics, and Astronomy, Queen's University, Kingston, Ontario (Canada)
- Department of Physics, University of Helsinki, Helsinki (Finland)
- Department of Planetary Sciences, University of Arizona, Tucson, Arizona (United States)
While computing an improved near-Earth object (NEO) steady-state orbital distribution model, we discovered in the numerical integrations the unexpected production of retrograde orbits for asteroids that had originally exited from the accepted main-belt source regions. Our model indicates that {approx}0.1% (a factor of two uncertainty) of the steady-state NEO population (perihelion q < 1.3 AU) is on retrograde orbits. These rare outcomes typically happen when asteroid orbits flip to a retrograde configuration while in the 3:1 mean-motion resonance with Jupiter and then live for {approx}0.001 to 100 Myr. The model predicts, given the estimated near-Earth asteroid (NEA) population, that a few retrograde 0.1-1 km NEAs should exist. Currently, there are two known MPC NEOs with asteroidal designations on retrograde orbits which we therefore claim could be escaped asteroids instead of devolatilized comets. This retrograde NEA population may also answer a long-standing question in the meteoritical literature regarding the origin of high-strength, high-velocity meteoroids on retrograde orbits.
- OSTI ID:
- 22047881
- Journal Information:
- Astrophysical Journal Letters, Vol. 749, Issue 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 2041-8205
- Country of Publication:
- United States
- Language:
- English
Similar Records
Shaping of Earth-crossing asteroids by tidal forces
Physical properties of asteroids in comet-like orbits in infrared asteroid survey catalogs