10 of the tributaries flowing into the Amazon river are as big as the Mississippi river.
41
Every year, Alaska has about 5,000 earthquakes.
31
If Antarctica's ice sheets melted, the worlds oceans would rise by 60 to 65 metres (200 - 210ft) - everywhere
181
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
Forest fires move faster uphill than downhill.
52
Europe is the only continent without a desert.
62
The Dallas/Ft. Worth airport is larger than New York City's Manhattan Island.
62