We wonder all the time about the possibility of a visit to Earth from some other planet. But we get deliveries from outer space all the time; just get up really early and look toward the constellation Orion for the latest active meteor shower.
The chunks that actually land on the surface give clues to the formation of our solar system, and Tim Gregory, a cosmochemist (!) writes about them in the book Meteorite: How Stones from Outer Space Made Our World.
Tim is familiar with the composition, feel, and even smell of these space chunks. He joins us for a visit on the subject matter.
Video bonus: Tim's video on polishing and etching a chunk of meteorite.