Why do some fish thrive in salt water and others in fresh? And what happens if you, say, drop a saltwater shark into a fresh water swimming pool? Here's the science!

We experience extreme hot and cold temperatures on Earth, but they're nothing compared to the temperature extremes we've created in labs, not to mention the Universe at large. Do these hot and cold extremes have a limit?

Astronomers recently made a huge discovery—there may be life on Venus. But what does it really mean when we say we've discovered the potential for life on the second rock from the Sun? Don't go searching for aliens just yet.

How many days can it take to control a large wildfire? (More than you think.) Who fights wildfires? (You may be surprised!) What tools and methods do firefighters use to control, extinguish, and prevent them?