41% of the moon is not visible from earth at any time.
103
Any space vehicle must move at a rate of 7 miles per second in order to escape the earth's gravitational pull.
121
More than 20 million meteoroids enter Earth's atmosphere every day.
139
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
On Titan, Saturn's largest moon, the atmosphere is so thick and the gravity so low that humans could fly through it by flapping "wings" attached to their arms.
7
Jupiter's moon Ganymede, is larger than the planet Mercury!
149
There's a mysterious dwarf planet between Mars and Jupiter called 'Ceres' which has never been visited by spacecraft or photographed in detail, however, Earth-bound telescopes reveal a large bright shining spot on the surface of this planet, the origin and nature of which are unknown.
5
One pinhead of the sun's energy is enough to kill a person at a distance of 160 kilometers.
277