ヤルコフスキー効果
Without direct measurement, it is very hard to predict the exact result of the Yarkovsky effect on a given asteroid's orbit. This is because the magnitude of the effect depends on many variables that are hard to determine from the limited observational information that is available. These include the exact shape of the asteroid, its orientation, and its albedo. Calculations are further complicated by the effects of shadowing and thermal "reillumination", whether caused by local craters or a possible overall concave shape. The Yarkovsky effect also competes with radiation pressure, whose net effect may cause similar small long-term forces for bodies with albedo variations or non-spherical shapes.