The population of the Earth has more than doubled since 1950.
151
Any space vehicle must move at a rate of 7 miles per second in order to escape the earth's gravitational pull.
121
The Earth weighs around 6,600,000,000,000,000,000,000 tons (5,940 billion billion metric tons)!
221
A lightning bolt generates temperatures five times hotter than those found at the sun's surface!
127
Pluto is smaller than Russia.
9
The heart of an astronaut actually gets smaller when in outer space.
216
The Sun and Moon appear to be the same size because the moon is 400 times smaller than the Sun, but 400 times closer to Earth.
13
Jupiter's moon Ganymede, is larger than the planet Mercury!
149