Supported by the National Natural Science Foundation of China (Grant Nos. 40173006 and 40325007);Key Research Project of Ministry of Education, China (Grant No. 03106);National Basic Research Program of China (Grant No. 2004CB720506)
Extraterrestrial particles have higher 3He/4He ratios than those of terrestrial sediments ( > 100 Ra versus < 0.03 Ra, where Ra is the 3He/4He ratio normalized to the atmospheric value of 1.4×10?6). The inter- planet...