To seek the answer to this mystery, NASA has launched five satellites aboard a Delta rocket from Florida to train their instruments on the northern and southern lights.The project is called THEMIS .是什么意思_To seek the answer to this mystery, NASA has launched five satellites aboard a Delta rocket from Florida to train their instruments on the northern and southern lights.The project is called THEMIS .在线翻译_英语_读音_用法_例句