Viking 2

Key facts

Mission & specifications

Mission

Viking 2 was the twin of Viking 1, and together they formed NASA's first sustained assault on the question of life on Mars. Launched on 9 September 1975, it consisted of an orbiter and a lander. The orbiter reached Mars in August 1976, and on 3 September the lander touched down in Utopia Planitia, a flat northern plain on the far side of the planet from its sibling. Like Viking 1, it carried a compact biology laboratory that scooped up soil and tested it for the chemical signatures of living organisms. The results were tantalising but ambiguous: some experiments produced reactions that mimicked life, yet the instruments found no organic molecules in the soil, and most scientists concluded that exotic, highly reactive surface chemistry — not biology — was responsible. The debate has never fully died. Viking 2's cameras captured another striking sight: a thin layer of water-ice frost that formed on the rocks and soil during the Martian winter, the first frost ever photographed on another planet. The lander operated until April 1980, far beyond its planned life, while its orbiter mapped Mars from above. Between them, the two Vikings defined Mars science for a generation.

1. 1975Launch toward MarsLaunch

   A Titan IIIE-Centaur sends the Viking 2 orbiter and lander on their way.

2. 1976Enters orbit around MarsArrival

   The orbiter arrives and scouts the northern plains for a safe landing site.

3. 1976Landing in Utopia PlanitiaLanding

   Touches down on the far side of Mars from Viking 1.

4. 1976Biology experimentsMilestone

   The life-detection tests return the same ambiguous results as Viking 1; no organics are found.

5. 1980Last transmissionMission end

   Falls silent after years of work, having photographed the first frost on the Martian surface.

Images

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