Most people felt pretty confident that, that crater was 180 kilometers across based on the most prominent set of circular features there.

多数人很确信，那个陨石坑直径达180千米，这是据最主要的一层环状结构测量所得。

And in those areas they actually found a fairly circular feature, and in that, they deduced that that might be an impact crater.

他们在那些区域发现了相当圆的地形，就这样他们推测那可能是个撞击坑。