Abstract
Although chondrules formed under levitated environment in space, most of the previous reproduction experiments have been carried out under non-levitated environment. Therefore, we carried out new reproduction experiments on chondrule formation by using a gas jet levitator. The experimental results show that nucleation of the levitated melts is very difficult and most chondrule melts turned to be glass by cooling. Because chondrule melts had to nucleate and crystallize in some way, we examined a hypothesis that the chondrule melts contacted with cosmic dusts and crystallized. To investigate the seeding effect, um-size silicate dust particles were accreted to the supercooled levitated melt and the results showed that the nucleation rate of the melts was promoted by collision with silicate particles and the melts crystallized in spite of at a narrow temperature range. And similar textures observed in pyroxene chondrules could be reproduced from very large supercooled enstatite melt (500-860 K).
