More than a dozen men have stood on the surface of the moon, but only three have been to Challenger Deep in the Marianas Trench, the deepest known spot in the ocean.
17
Every person in the world can fit in Texas and be given over 1000 sq ft in which to live.
14
Forest fires move faster uphill than downhill.
52
An earthquake on Dec. 16, 1811 caused parts of the Mississippi River to flow backwards.
243
Europe is the only continent without a desert.
62
It takes a drop of ocean water more than 1,000 years to circulate around the world.
61
The water of the Antarctica is so cold that nothing can rot there.
334
There's a lake under Antarctica that is 25 million years old called Lake Vostok.
109