Half a Century After Viking 2: How Mars Exploration Has Evolved

When Viking 2 arrived on Utopia Planitia in 1976, it delivered the most detailed Martian photographs of its era and conducted the first soil experiments searching for life, though no definitive microbes were found. Over the ensuing five decades, increasingly sophisticated orbiters and rovers have mapped the planet in unprecedented detail, revealing phenomena such as seasonal CO₂-driven “spider” patterns, the geometrically intriguing Inca City formation, and transient dark streaks on slopes.

The Perseverance rover’s work in Jezero crater has uncovered sedimentary layers and volcanic rocks that interacted with water, offering clues to ancient river and lake environments. Some mineral samples exhibit features that scientists are evaluating as potential biosignatures, though alternative non-biological explanations remain plausible. Collectively, these discoveries have transformed our view of Mars from a barren world to one that once hosted extensive water activity and may have supported life.