In space, astronauts cannot cry properly, because there is no gravity, so the tears can't flow down their faces!
175
The Space Shuttle main engine weighs 1/7th as much as a train engine but delivers as much horsepower as 39 locomotives.
147
The population of the Earth has more than doubled since 1950.
151
Approximately 115 tons of ocean salt spray enters the earth's atmosphere each second.
100
The Earth gets heavier each day by tons, as meteoric dust settles on it.
118
Today's top fuel dragsters take off with more force than the space shuttle.
120
An organisation called Mars One is planning to establish a permanent colony of humans on Mars by 2023.
9