The world’s largest crane is a true engineering marvel, capable of lifting 5,000 tons. This video explores how it works, what it’s used for, and what it feels like to operate such a massive machine.

For sale: A 54-pound (25-kilogram) rock. Estimated auction price: $2 million to $4 million. Why so expensive? It's the largest piece of Mars ever found on Earth. Sotheby's in New York will be ...