The planetary defense officer focuses on the detection of dangerous asteroids and comets that might threaten the Earth (as in the movies “Don’t Look Up” and “Armageddon” and “Deep Impact”), and explores technologies for preventing such a thing from happening. This job is not to be confused with the NASA planetary protection officer, who is supposed to keep Earth’s microbes from contaminating other worlds or hypothetical alien microbes from coming to Earth, as in “The Andromeda Strain.”

The Double Asteroid Redirection Test (DART) was conceived as NASA’s first planetary defense mission. A golf-cart-size spacecraft was launched in November 2021 from California. If all went precisely as planned, its 10-month journey would end at precisely 7:14 p.m. Eastern on Monday, Sept. 26, when it would collide with an asteroid named Dimorphos.