Title: Solar radiation pressure on (99942) Apophis
Authors: J. Žižkaa, b, and D. Vokrouhlickýa, ,
a Institute of Astronomy, Charles University, V Holešovičkách 2, 18000 Prague 8, Czech Republic
b Nicholas Copernicus Observatory and Planetarium, Kravı´ hora 2, 61600 Brno, Czech Republic
Abstract: Near-Earth asteroid (99942) Apophis currently resides among the top positions on the list of objects with small, yet non-zero impact probability with the Earth. For that reason an unusual observational and theoretical effort has been dedicated to precisely characterize its future orbit. Here we discuss orbital perturbation of Apophis due to incident and reflected solar radiation pressure (SRP). We both revisit recent analytical estimate of the SRP effects for this body and also formulate a numerical approach allowing us to compute the SRP orbital perturbation under general assumptions. Contrary to some previous results, we show that SRP has a much smaller effect on the Apophis trajectory than does the thermal re-radiation force which produces the Yarkovsky effect. When the Yarkovsky effect becomes constrained enough in the future, our approach may be used to improve the orbit determination for this asteroid.
Link: Article ("Apophis asteroid encounter in 2013 should help answer impact worries")
This area will cover relevant news of the threat to the planet from Near Earth Objects (NEOs) including concepts and designs for mitigation. All opinions are those of the author.
10 November 2010
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