Long-term impact risk for (101955) 1999 RQ36

TL;DR

This paper assesses the long-term impact risk of asteroid 1999 RQ36, highlighting the importance of the Yarkovsky effect and the challenges it poses for impact probability estimation over centuries.

Contribution

It introduces a detailed analysis of impact probabilities beyond 100 years, emphasizing the role of the Yarkovsky effect and asteroid thermal properties in long-term impact assessment.

Findings

Impact probability of ~0.001 for 1999 RQ36.

Two main impact routes identified for 2182.

Yarkovsky effect significantly influences long-term impact predictions.

Abstract

The potentially hazardous asteroid (101955) 1999 RQ36 has the possibility of collision with the Earth in the latter half of the 22nd century, well beyond the traditional 100-year time horizon for routine impact monitoring. The probabilities accumulate to a total impact probability of approximately 10E-3, with a pair of closely related routes to impact in 2182 comprising more than half of the total. The analysis of impact possibilities so far in the future is strongly dependent on the action of the Yarkovsky effect, which raises new challenges in the careful assessment of longer term impact hazards. Even for asteroids with very precisely determined orbits, a future close approach to Earth can scatter the possible trajectories to the point that the problem becomes like that of a newly discovered asteroid with a weakly determined orbit. If the scattering takes place late enough so that the target plane uncertainty is dominated by Yarkovsky accelerations then the thermal properties of the asteroid,which are typically unknown, play a major role in the impact assessment. In contrast, if the strong planetary interaction takes place sooner, while the Yarkovsky dispersion is still relatively small compared to that derived from the measurements, then precise modeling of the nongravitational acceleration may be unnecessary.