An organisation called Mars One is planning to establish a permanent colony of humans on Mars by 2023.
9
It takes eight and a half minutes for light to get from the sun to earth.
159
Saturn's rings are about 500,000 miles in circumference but only about a foot thick.
160
A comet's tail always points away from the sun.
2
The earth travels through space at 660,000 miles per hour.
189
The earth rotates more slowly on its axis in March than in September.
145
Approximately 115 tons of ocean salt spray enters the earth's atmosphere each second.
100
The Earth weighs around 6,600,000,000,000,000,000,000 tons (5,940 billion billion metric tons)!
221