Evidence of life on Mars was torched to ash during NASA’s first touchdown mission on the Red Planet more than 40 years ago, scientists claim.
The space agency’s Viking Landers, the first craft to land on the Martian surface, may have accidentally found and obliterated the raw materials for life using their gas instruments, according to a new study published in the Journal of Geophysical Research: Planets.
NASA’s Viking 1 and 2 missions landed on Mars ten months apart in 1975 and 1976.
Though designed to last just 90 days, the landers wound up collecting data on the Red Planet for over six years, including 4,500 close-up images of the Martian surface and a whopping 50,000 orbiting snaps, mapping 97 percent of the planet.
But one thing was missing: the Viking craft hadn’t found the organics they set out for, which scientists long suspected existed on Mars.
They were proved right last month when NASA revealed that its Curiosity Rover – a successor to Viking – had found “building blocks of life” in a three-billion-year-old lakebed on the planet.
The space agency knew that small, carbon-rich meteorites regularly pelted Mars, meaning its surface should’ve been covered in organic molecules.
“It was just completely unexpected and inconsistent with what we knew,” Chris McKay, a planetary scientist at NASA’s Ames Research Center and author of the new paper, told New Scientist.
In order to test the Martian soil, the Viking landers used gas instruments to heat their samples into releasing vapors that they could then examine for the presence of organic material.
The new study claims that in doing so, the probes would have burned up a highly-flammable salt known as perchlorate in the Martian soil.
This compound, used to make fireworks on Earth, was found by NASA’s Phoenix lander on the Red Planet in 2008.
But the discovery still didn’t offer conclusive proof that the Viking landers had screwed up all those decades ago, so the investigation continued.
Then came a breakthrough when the Curiosity Rover recently discovered chlorobenzene, which is created when carbon molecules burn with perchlorate.
Digging further into the Viking data, researchers found that the landers also detected chlorobenzene, which they suggest came about when the soil samples were burnt by the landers.
The study concludes that the probes did find organic material, but destroyed any sign of them when they heated perchlorate in the samples.
However, Melissa Guzman – a scientist at the LATMOS research center in France who also worked on the paper – has put forward another possible scenario.
She claims that the chlorobenzene Viking found may have come from material they carried from Earth to Mars.
But Dr. Daniel Glavin, from NASA’s Goddard Space Flight Center in Maryland, declared that the paper finally proves that the probes found evidence for life on the planet.
“This paper really seals the deal,” the scientist, who was not involved in the study, told New Scientist.
Along with the recent Curiosity data, the latest research indicates organic material is scattered across a range of sites on Mars — meaning more discoveries could be on the horizon.