Astronomy12 papers
The Yarkovsky effect
IŽ
Ivana Milić Žitnik
All Reviews
AstronomyMust Read
advanced
The Yarkovsky effect for 99942 Apophis
David Vokrouhlický et al. (2015)
- Published
- May 1, 2015
- Journal
- Icarus · Vol. 252
- DOI
- 10.1016/j.icarus.2015.01.011
At a Glance
Models Apophis’ Yarkovsky drift despite tumbling, tightening post-2029 trajectory and late-century impact probabilities.
Summary
This paper matters because Apophis’ 2029 Earth flyby makes tiny non-gravitational forces dominate long-term impact-risk forecasts. Using newly measured shape, size, thermophysics, and a confirmed tumbling rotation state, the authors compute Apophis’ Yarkovsky-driven semimajor-axis drift and show tumbling does not significantly suppress the effect, validating a widely used simplification for km-scale tumblers. They predict a drift of about −12.8±3.6×10⁻⁴ au/Myr (1σ) and find current astrometry only weakly constrains Yarkovsky, but is consistent with the model. Mapping combined uncertainties onto the 2029 b-plane updates keyhole impact odds: no impacts before 2060, but residual post-2060 probabilities remain at the few-per-million level, dominated by a 2068 return scenario.
Method Snapshot
Numerical thermophysical modeling on a polyhedral shape with non-principal-axis rotation, combined with orbit fitting and 2029 b-plane/keyhole uncertainty mapping.
Background
Background in asteroid orbital dynamics (Yarkovsky effect, close-encounter uncertainty growth) and basic thermophysics of radiative heat recoil.