Sotheby's is putting some rare items up for auction, including what it calls the largest piece of Mars ever found on Earth. The auction house is also selling a juvenile ceratosaurus dinosaur skeleton ...

For sale: A 25 kilogram rock. Estimated auction price: $3-$6 million. Why so expensive? It's the largest piece of Mars ever ...

The very first auction that Christie’s conducted, back in London in 1766, was a single-owner collection sale of objects only identified as “the property of a Noble Personage (Deceas’d).” Presumably, ...