Physics Today: Veteran NASA astronaut and fellow of the American Geophysical Union Piers Sellers is scheduled to blast off on Friday on board the space shuttle Atlantis. Sellers will take with him two objects of significance to physicists: a piece of the apple tree that grew in Isaac Newton’s garden and the Nobel Prize medal that was awarded in 2006 to John Mather for his work on the cosmic microwave background. Before joining the astronaut corps, Sellers was a researcher at NASA’s Goddard Space Flight Center, where Mather did his prize-winning work.