An organisation called Mars One is planning to establish a permanent colony of humans on Mars by 2023.
9
The population of the Earth has more than doubled since 1950.
151
A 100-pound person on Earth would weigh 38 pounds on Mars.
102
Any space vehicle must move at a rate of 7 miles per second in order to escape the earth's gravitational pull.
121
Saturn's rings are about 500,000 miles in circumference but only about a foot thick.
160
The earth rotates more slowly on its axis in March than in September.
145
The Space Shuttle main engine weighs 1/7th as much as a train engine but delivers as much horsepower as 39 locomotives.
147