Australia's Great Barrier Reef is 1,250 miles long!
45
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
More than 25% of the world's forests are in Siberia.
51
One cubic mile of seawater contains about 50 pounds of gold.
79
Mexico City is built on top of an underground resevoir!
47
The Sahara desert expands at about 1km per month.
90