D. Vokrouhlicky et A. Milani, Direct solar radiation pressure on the orbits of small near-Earth asteroids: observable effects?, ASTRON ASTR, 362(2), 2000, pp. 746-755
We consider the perturbations of Near-Earth Asteroid orbits due to direct s
olar radiation pressure (both the absorption and the reflection components)
. When the body is spherical and the surface albedo homogeneous the effect
is small (and only short-periodic). However, when at least one of these res
trictive and unrealistic assumptions is relaxed,long-term orbital effects a
ppear and they may potentially lead to observable displacement of the orbit
. We illustrate this conclusion by computing the orbital perturbations due
to radiation pressure for objects with an odd-zonal distribution of albedo
and for objects with ellipsoidal shape. Especially in the first case the ef
fects are large, due to the long-term perturbations of the semimajor axis.
For high-eccentricity orbits observed over a long interval of time, the (v/
c)-correction of the direct radiation pressure, known as Poynting-Robertson
effect, should be also considered. As an example we demonstrate that for t
he asteroid 1566 Icarus, during its next close approach to the Earth, the o
rbit displacement due to the direct solar radiation forces might be, under
reasonable assumptions. comparable to the orbit determination uncertainty,
thus potentially observable.