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Near Earth Asteroids with measurable Yarkovsky effect

D. Farnocchia et al. (2013)

Published
May 1, 2013
Journal
Icarus · Vol. 224 · No. 1
DOI
10.1016/j.icarus.2013.02.004

At a Glance

Robustly measures Yarkovsky-driven orbital drift for 21 NEAs using precision dynamics and careful astrometry, improving spin/impact inferences.

Summary

This paper expands direct evidence for the Yarkovsky effect in near-Earth asteroids by extracting a measurable semimajor-axis drift from orbit fits while tightly controlling for modeling and astrometric systematics. Using a high-fidelity force model (including relativistic terms and 16 massive asteroids) plus debiased/weighted astrometry, the authors identify 21 reliable detections with SNR>3 and show most drifts are negative, implying a strong excess of retrograde rotators. They connect that retrograde excess to NEA delivery via resonances (especially ν6) and show measured drifts can constrain physical properties like bulk density/thermal inertia when some spin/size information exists. The work also clarifies when Yarkovsky becomes the dominant uncertainty in long-term impact prediction, with implications for cases like 1950 DA and future monitoring horizons.

Method Snapshot

Simultaneous orbit determination with an added one-parameter transverse nongravitational acceleration (A2) to fit Yarkovsky-induced drift from radar+optical astrometry.

Background

Background in celestial mechanics/orbit determination and basic thermal recoil physics (Yarkovsky/YORP) for small bodies.