Which planet did the "Viking 1" spacecraft send surface images of, starting in 1976?

The story behind the answer

Mars is correct. NASA’s Viking 1 became the first successful long-lived lander on Mars, touching down in Chryse Planitia on July 20, 1976 and sending back the first high-resolution color images from the Martian surface. Its orbiter mapped the planet while the lander photographed rocks, dunes, and the thin pink sky, and analyzed soil chemistry.

To distinguish the options: Jupiter and Saturn are gas giants with no solid surface to land on, and Venus’s surface photos came from the Soviet Venera missions, not Viking. Memory tip: think “Viking on the red planet”—a Viking’s rusty shield matches Mars’s iron-rich, reddish soil. Viking 1 and Viking 2 both landed in 1976, paving the way for Pathfinder, Spirit, Opportunity, Curiosity, and Perseverance.