== Stopped in mid-air? == 

 :A smaller ice cube will be stopped in mid-air and explode. An ice cube with a diameter of 50 m or more, however, may also be stopped in mid-air, as long as it comes in at a very low angle and thus has to pierce through a lot of atmosphere. 

 How can it be "stopped in mid-air"? Surely it's still moving before it explodes!