The Viking 1 Lander sampling arm and the deep trenches it dug as part of the surface composition and biology experiments on Mars. Images credit: NASA and Roel van der Hoorn.

Forty Years Ago, We Landed On Mars… And Found Life?

When the Viking landers ran their three experiments looking for life, one came up positive. That’s still a mystery.

“This suggests a robust biological response. These analyses support the interpretation that the Viking LR experiment did detect extant microbial life on Mars.” -Bianciardi, Miller, Straat and Levin

In 2016, our understanding of Mars has been helped along tremendously by a slew of successful rovers, landers, and orbiting missions. We’ve mapped the Martian surface completely and at high-resolution; we’ve roamed more than a marathon’s worth of distance on the surface, discovering meteorites, crater interiors, dunes and frozen water; we’ve seen mysterious methane-rich “vents” of gas on the surface; we’ve discovered salty flowing liquid water on the surface itself and dried-up riverbeds. And perhaps most spectacularly, we’ve discovered — up close — the presence of what we call Martian blueberries, which are hematite spheres produced here on Earth by organic processes and living creatures in an aquatic environment. Given how Earth-like Mars’ past may have been, it raises the most important question we’ve ever asked of another world: is there now, or was there ever, life on Mars?