Astronomy15 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 GlanceAI
Models Apophis’ Yarkovsky drift despite tumbling, tightening post-2029 trajectory and late-century impact probabilities.
SummaryAI
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 SnapshotAI
Numerical thermophysical modeling on a polyhedral shape with non-principal-axis rotation, combined with orbit fitting and 2029 b-plane/keyhole uncertainty mapping.
BackgroundAI
Background in asteroid orbital dynamics (Yarkovsky effect, close-encounter uncertainty growth) and basic thermophysics of radiative heat recoil.
They used the determined rotation state, shape, size and thermophysical model of Apophis to predict the strength of the Yarkovsky effect in its orbit.
— IŽ