Sotheby's is auctioning a 54-pound Martian meteorite, NWA 16788, the largest ever found on Earth, for an estimated $2 million to $4 million. Discovered in Niger, it's 70% larger than the previous largest Martian meteorite and represents nearly 7% of all Martian material on Earth. The auction also includes a juvenile Ceratosaurus skeleton estimated at $4 million to $6 million. The meteorite's journey involved a massive asteroid strike on Mars, followed by a 140 million-mile trip to Earth, where it landed in recent years.

Prepared by Olivia Bennett and reviewed by editorial team.