10 of the tributaries flowing into the Amazon river are as big as the Mississippi river.
41
Australia's Great Barrier Reef is 1,250 miles long!
45
If Manhattan had the same population density as Alaska, there would only be 15 people living there.
138
The Niagara Falls moves upstream at an average rate of about 295ft a century!
48
There are more than 50,000 earthquakes throughout the world every year!
47
Due to gravitational effects, you weigh slightly less when the moon is directly overhead.
55
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