The Perseverance rover landed on Mars on February 18, 2021 on the floor of a crater that held a deep lake about 3.5 billion years ago. The mission's goals are to interpret the rocks deposited on the crater floor, seek evidence of possible ancient life recorded in those rocks, and prepare a collection of rock samples for possible return to Earth by future missions. I am Project Scientist for the mission, and in this talk I'll explain this mission's motivations, activities, and discoveries in its first nine months.