Ask Smithsonian: Why Are Lakes Freshwater and Oceans Saltwater?

Erosion, evaporation, and a leaky faucet, our host Eric Schulze breaks it all down. (1:15)

Ask Smithsonian is a weekly video series that unravels some of science's most surprising mysteries. The series is made possible through the support of GEICO. Smithsonian members could save even MORE with a special GEICO #MemberDiscount on auto insurance.

Have a question in mind? It's your turn to Ask Smithsonian.

Latest Videos

Preview thumbnail for video'How America's Public Parks Were Born
How America's Public Parks Were Born (1:50)
Preview thumbnail for video'The Egyptian Pharaoh With the Biggest Ego
The Egyptian Pharaoh With the Biggest Ego (2:33)
Preview thumbnail for video'How Did a Grizzly Bear Get on California's Flag?
How Did a Grizzly Bear Get on California's Flag? (3:22)
Preview thumbnail for video'Hammerhead vs. Stingray
Hammerhead vs. Stingray (2:25)
Preview thumbnail for video'The Incredible Things a Hammerhead's Nose Can Do
The Incredible Things a Hammerhead's Nose Can Do (1:24)
Preview thumbnail for video'This Woman Was Picasso, Hemingway and Fitzgerald's Muse
This Woman Was Picasso, Hemingway and Fitzgerald's Muse (4:24)
Preview thumbnail for video'The Colonial Settlement That Vanished Into Thin Air
The Colonial Settlement That Vanished Into Thin Air (2:10)
Preview thumbnail for video'Why Brown Bears Are Misunderstood
Why Brown Bears Are Misunderstood (2:17)
Preview thumbnail for video'Ways to Avoid Losing Oxygen in a Submarine
Ways to Avoid Losing Oxygen in a Submarine (2:30)