Why space shuttle exhaust races to the poles

SPACE shuttle exhaust plumes tend to move and spread faster than they should – seemingly because they are fast-tracked inside a low-density part of the atmosphere. The shuttle leaves over 300 tonnes of water in the atmosphere and a 1000-kilometre-long exhaust trail. This creates a plume, parts of which travel to the poles far faster than expected. Now Robert Meier of George Mason University in Fairfax, Virginia,