Mars, seen through the instruments NASA had trained on it by the late 1970s: ground-based telescopes, the Mariner spacecraft that flew past and later orbited the planet, and the two Viking landers that reached the surface in 1976. This NASA-produced film walks through what each generation of observation added. Telescopes on Earth first mapped Mars's polar caps and seasonal changes from a distance. Mariner's flybys and orbital passes then supplied the first close photographs, revealing canyons, extinct volcanoes, and cratered deserts rather than the smooth world earlier observers had guessed at. The Viking missions go furthest, with orbiter cameras charting the surface in detail and landers testing Martian soil directly for signs of biological activity. The film treats the soil experiments' ambiguous results as an open question rather than a settled answer, and notes the atmosphere's similarities to Earth's as part of what keeps scientific interest in the planet alive. It is a period snapshot of Mars knowledge at the exact point before later orbiters and rovers moved the story forward.