Hokkaido University Graduate School of Science
INTEC Inc.
Hokkaido University Graduate School of Science
出版者
宇宙航空研究開発機構宇宙科学研究本部
出版者（英）
Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency (JAXA/ISAS)
雑誌名
第37回月・惑星シンポジウム
雑誌名(英)
Proceedings of the 37th ISAS Lunar and Planetary Symposium
ページ
65 - 68
発行年
2004-02
抄録（英）
The Galilean satellites are considered to have been formed in the Jovian subnebula, which was produced during the gas capture of proto-Jupiter, according to the similar scenario to the planet formation in the solar nebula. However, it is not well understood whether or not all of elementary steps of the satellite formation are described by the scaled-down planet formation processes because the subnebula is so different from the solar nebula in temperature, density, time scale, and so on. In this study, concerned is the collisional growth of dust, the first stage of the satellite formation. During the growth due to mutual collisions, the dust particles fall toward Jupiter due to gas drag. Falling velocity strongly depends on the size of dust particles, and the particles with radius of 10(exp -2) to 1 m fall fastest. For a minimum mass Jovian subnebula model (Mosqueira and Estrada, 2003), the maximum falling velocity is about 120 m/s at the present orbit of Ganymede. At this velocity, a dust particle would reach Jupiter in three months. To form satellitesimals, it is necessary that the time scale of dust growth through this dangerous size range is shorter than that of falling. The time scale of collisional growth is estimated by performing a numerical computation taking it into account that dust particles can not stick when they collide in a very high velocity. Given is 10 m/s as the critical velocity for sticking (Dominik and Tielens, 1996). As a result, obtained is about one month as a minimum growth time. This indicates that the formation of satellitesimals is difficult without considering the effect of the formation of dust concentrated region or (and) the mechanism to increase the critical velocity to form satellitesimals.
The effect of imperfect sticking on the collisional growth of dust in the Jovian subnebula
