#1 New York Times bestseller * Best Book of the Year from The Washington Post, Publishers Weekly, New York Public Library, Chicago Public Library. The One and Only Ivan meets The Wild Robot in this unique and deeply moving middle grade novel about the journey of a fictional Mars rover, from the Newbery Honor-winning author of Other Words for Home. Meet Resilience, a Mars rover determined to live up to his name. Res was built to explore Mars. He was not built to have human emotions. But as he learns new things from the NASA scientists who assemble him, he begins to develop humanlike feelings. Maybe there's a problem with his programming.... Human emotions or not, launch day comes, and Res blasts off to Mars, accompanied by a friendly drone helicopter named Fly. But Res quickly discovers that Mars is a dangerous place filled with dust storms and giant cliffs. As he navigates Mars's difficult landscape, Res is tested in ways that go beyond space exploration. As millions of people back on Earth follow his progress, will Res have the determination, courage, and resilience to succeed...and survive?