NASA May Have Discovered And Accidentally Burned Organic Matter On Mars Years Ago
NASA's Curiosity rover recently uncovered complex organic molecules on Mars' surface, opening the doors to the possibility of ancient life on the Red Planet.
However, it might not even be the first time this has happened.
Back in 1976, another NASA probe may have made a similar discovery — only to accidentally burn it all away, a study published in the Journal of Geophysical Research: Planets reveals.
The Viking Missions
Scientists have long suspected that Mars is home to many organic materials since the planet is constantly getting pelted with carbon-rich micrometeorites and dust that's flying around in space, according to New Scientist.
With this in mind, a pair of Viking landers were sent to Mars to hunt for organics, particularly hints of carbon in the surface that was expected to be sure thing. To the shock of the NASA scientists, Viking 1 and 2 did not find any trace.
The absence of organic molecules befuddled scientists who point out that it was inconsistent with the data they have on the Red Planet.
Viking May Have Set Their Organics Ablaze
A potential answer for the mystery came up when the Phoenix spacecraft sailed to Mars in 2008 and discovered the presence of a type of salt in Mars called perchlorate.
Perchlorate is rare on Earth, often used for fireworks and becomes extremely explosive when exposed to high temperatures, according to Space.com.
The planet's surface isn't hot enough for it to burn, but the Viking instruments uses heat to find organic molecules. Since the perchlorate is in the soil samples, scientists surmise that the salt combined with the heat could have ignited, incinerating all traces of organics from the samples collected and leaving the scientists empty-handed for decades.
Curiosity's recent discoveries provided another piece of evidence to support the theory that Viking burned away organic compounds found 40 years ago. One of the molecules collected was chlorobenzene, which is produced when carbon is burned with perchlorate. Scientists believe that it was created when the soil samples were heated by the Viking landers.
When the researchers reviewed the Viking data, they found that the 1976 spacecrafts also detected chlorobenzene back then.
"We conclude the chlorine component of the chlorobenzene is martian, and the carbon molecule of the chlorobenzene is consistent with a martian origin, though we cannot fully rule out instrument contamination," the scientists wrote in the recently released paper.
The scientific community remain divided on the issue with some skeptics pointing out that the chlorobenzene came from Earth. However, it is a plausible explanation for the absence of organics in the 1970s, especially since Curiosity was able to find some in the recent trip to Mars.