Yarkovsky effect

The Yarkovsky effect was described in 1900 by the Russian-Polish engineer Ivan Ossipowitsch Jarkowski and named after him. He explains the influence of a fluctuating surface heating of asteroids on their trajectory.

Description

The cause of the Yarkovsky effect lies in the different degrees of heating of the asteroid surfaces ( " Sites"). The " Afternoon page " is warmer than the " morning side ", as the latter is cooled by the previous night. The degree of heating, and the strength of the effect even depend inter alia on the rotation, the surface characteristics ( reflectance or albedo ), and the thermal conductivity of asteroids. From the warmer side more heat radiation it emits as of the cooler; According to the different radiation pressure, there is a ( very small ) force to the heavenly bodies. Of particular interest is the effect of force is tangential to the orbit, which leads to an acceleration or deceleration of the celestial body. As a consequence, the orbits of asteroids that rotate in the direction of their flight path around its own axis ( prograde ), pushed outward and those running their own rotation opposite to the trajectory ( retrograde), changed inside.

The Yarkovsky effect was confirmed in the case of the asteroid Golevka. Golevka is a relatively unobtrusive, low-earth orbit average sized object around 0.5 km Size. Despite the very low strength of the effect of the asteroid was deflected in only 12 years, about 15 km from its path.

Further research of the Polish Adam Mickiewicz University showed that generally are not caused only by collisions, but to a large extent by the Yarkovsky effect track changes of asteroids towards inner solar system. Objects that orbit in the asteroid belt between Mars and Jupiter can be in this way to a near-Earth object that crosses the orbit of Earth.