The first crater appeared last summer.

第一个坑是在去年夏天出现。

When reindeer herders discovered the first crater there was a lot of speculation on how it was formed, with theories ranging from asteroids, stray missiles to aliens.

当养鹿人发现第一个火山口关于它是怎样形成的有很多猜测，从小行星到偏离轨道的导弹再到外星人。