This effect was predicted back in the early 1970s, but researchers were only finally able to observe it during the total solar eclipse of July 22, 2009.
此项效应早在20世纪的70年代就被预计到了，可是研究者最后只能在2009年7月22日的日全食时才能观察到。
The solar eclipse of July 22, 2009 was a total solar eclipse.
本月22日出现的日食就是非常难得一见的日全食。
应用推荐