Summer on Uranus lasts for 21 years.
358
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
The Space Shuttle main engine weighs 1/7th as much as a train engine but delivers as much horsepower as 39 locomotives.
147
Sound doesn't travel in space.
255
A lightning bolt generates temperatures five times hotter than those found at the sun's surface!
127
Venus is the only planet that rotates clockwise.
310
The earth travels through space at 660,000 miles per hour.
189
More than 20 million meteoroids enter Earth's atmosphere every day.
139