Viking 1 Lander
First successful Mars long-duration station · Thomas Mutch Memorial Station · Chryse Planitia
Resting Site
Chryse Planitia (The Golden Plain)
22.271° N, 312.049° E
Surface Lifespan
2,245 Sols
6.1 Earth years active
Power Source
2× SNAP-19 RTG
70 Watts (Plutonium-238)
HiRISE Imagery
PSP_001521_2025
Resolved from 280 km orbit
Lander Mass
572 kg
572 kg touchdown dry mass
Labeled Release (LR) Radioactive Gas Simulator
In 1976, Viking dropped a broth of nutrients tagged with radioactive Carbon-14 (¹⁴C) into Martian soil. The response shocked the scientific world.
The Perchlorate Salt Revolution
32 years later, Phoenix discovered perchlorate salts (ClO₄⁻) across Mars. Surface radiation turns perchlorates into superoxides.
When the nutrient broth was poured, the superoxides chemically ripped the amino acids apart into ¹⁴CO₂—explaining the spike completely without needing living biology!
PI: Gilbert V. Levin & Patricia Ann Straat
The 4 Onboard Soil Instruments
0.115 ml of carbon-14 labeled nutrient broth injected into 0.5 cm³ surface regolith
Outcome: Immediate, explosive evolution of radioactive 14CO2 gas (>10,000 counts per minute). When pre-heated to 160°C (control), the soil produced virtually zero gas.
Soil heated in an oven to 50°C, 200°C, 350°C, and 500°C to volatilize organic molecules
Outcome: Found zero organic molecules above the instrument detection threshold of 1 part per billion (even less than Apollo Moon rocks).
Regolith exposed first to moisture (humidity) and then submerged in rich 'chicken soup' nutrient medium
Outcome: A sudden pulse of oxygen (O2) was released the moment humidity touched the soil, but adding liquid nutrient produced no sustained gas output.
Soil illuminated by simulated solar light in an atmosphere of 14CO2 and 14CO to test for photosynthesis
Outcome: A tiny amount of carbon was incorporated into the soil, but similar weak synthesis was observed in control tests held at high temperatures.
Look deeper: mission background
Authentic NASA Mission Context: Project Viking
In July 1976, Viking 1 became the first spacecraft to operate successfully on the surface of Mars. Its biology package was an engineering marvel: three miniature laboratories crammed into a one-cubic-foot automated container. The Labeled Release experiment gave a startling positive signal, but the lack of organic carbon detected by the GCMS puzzled scientists for decades until the 2008 Phoenix lander discovered oxidizing perchlorate salts in Martian soil.