Jarkowski effect
The Jarkowski effect (after the Russian engineer Iwan Ossipowitsch Jarkowski , who described it around 1900) explains the influence of the inconsistent surface heating of asteroids on their orbit .
description
The cause of the Jarkowski effect lies in the varying degrees of warming of the asteroid surfaces ("sides"). The "afternoon side" is warmer than the "morning side" because the latter has cooled down from the previous night. The degree of warming and the strength of the effect depend u. a. still depend on the rotation , the surface properties ( reflection or albedo ) and the thermal conductivity of the asteroid. More thermal radiation emanates from the warmer side than from the colder side; according to the different radiation pressure there is a (very small) force on the celestial body. Of particular interest is the force effect tangential to the orbit , which leads to an acceleration or deceleration of the celestial body. As a result, the orbits of asteroids, which rotate around its own axis in the direction of their trajectory are ( prograde ), pressed outwards and those whose self-rotation counter to the flight path (retrograde) extends changed inward.
The Jarkowski effect was confirmed in 2003 in the case of the asteroid Golevka and other objects. Golevka is a relatively inconspicuous, average-sized, near-earth object around 0.5 km in size. Despite the very low power of the effect, the asteroid was deflected about 15 km from its orbit in just 12 years.
Further research by the Polish Adam Mickiewicz University showed that general changes in the orbit of asteroids in the direction of the inner solar system are not only caused by collisions, but to a large extent by the Jarkowski effect. Objects that are in orbit in the asteroid belt between Mars and Jupiter can in this way become a near-earth object that crosses the orbit of the earth.
As a surface-proportional effect, its acceleration effect on celestial bodies with a small volume (mass) is stronger than on larger ones.
OSIRIS-REx will measure the Jarkowski effect of the asteroid (101955) Bennu .
See also
Web links
- The sun makes asteroids turn up (scienceticker.info, March 7, 2007)
- scholarpedia
Individual evidence
- ↑ Steve Chesley, et al .: Impact Risk Estimation and Assessment Scales. P. 656, in: Joseph N. Pelton, et al .: Handbook of cosmic hazards and planetary defense. Springer, Cham 2015, ISBN 978-3-319-03951-0 .