The Sahara desert expands at about 1km per month.
90
In 1850, only 8% of the people in California were women.
0
The Niagara Falls moves upstream at an average rate of about 295ft a century!
48
It takes a drop of ocean water more than 1,000 years to circulate around the world.
61
Israel's Dead Sea is 1,312 feet below sea level.
48
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