Dynamics of Earth‐crossing asteroids: the protected Toro orbits
- 54 Downloads
Some asteroids in Earth‐crossing orbits avoid close approaches by entering in a mean motion resonance whenever the distance between the two orbits is small. These orbits are ‘Toro class’ according to the classification of (Milani et al., 1989). This protection mechanism can be understood by a semi‐averaged model, in which the fast variables are removed and the dynamical variables are the critical argument and the semimajor axis, with dependence upon a slow parameter. The adiabatic invariant theory can be applied to this model and accounts for all the qualitative features of the orbits in this class, including the onset of the libration when the orbit distance is small. Because of the neglected perturbations by the other planets, this theory is approximate and the adiabatic invariant is conserved only with low accuracy moreover, the Toro state can be terminated by a close approach to another planet (typically Venus).
“Would you tell me, please, which way I ought to go from here?”
“That depends a good deal on where you want to get to,” said the Cat.
Alice in Wonderland, L. Carroll
Unable to display preview. Download preview PDF.
- 1.Baccili, S.: 1996, ‘Protezione per Risonanza dalle Collisioni con la Terra: gli Asteroidi della Classe Toro’, Thesis for the laurea degree in Mathematics, University of Pisa.Google Scholar
- 2.Barucci, M. A., Doressoundiram, A., Dotto, E., Farinella, P., Fulchignoni, M., Milani, A., Paolicchi, P., Perozzi, E. and Rossi, A.: 1998, ‘A rendezvous mission with an Earth approaching asteroid: a scenario for SMART-1’, proposal to the E. S. A., Meudon Astronomical Observatory.Google Scholar
- 3.Butcher, J. C.: 1987, The Numerical Analysis of Ordinary Differential Equations, Wiley, pp. 209–237.Google Scholar