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
One cubic mile of seawater contains about 50 pounds of gold.
79
An earthquake on Dec. 16, 1811 caused parts of the Mississippi River to flow backwards.
243
The Atlantic Ocean is saltier than the Pacific Ocean.
54
The state of Florida is bigger than England!
74
Every year, Alaska has about 5,000 earthquakes.
31