Life on Mars has been a topic of conversation for decades. We’re fascinated by the possibility of life on other planets, especially one as close to Earth as Mars. Since the 1970s, we’ve been trying to figure out if Mars is actually hospitable enough to house other lifeforms, and what we’ve found might actually surprise you. We already know that Mars was once closer to the Sun than it is today, and that liquid water was prevalent throughout the majority of the planet’s life. Astronomers believe that a planet must be in what they call the habitable zone in order to sustain the necessary properties for life.
Mars was once included in this zone, but due to the constant expansion of the universe, is now outside the boundaries. The same fate is destined for Earth as well, but this is only expected significantly further into the future.
A new paper published in the journal called Astrobiology reviews the last four decades of analysis of the Red Planet, and concludes that the possibility for life is more substantial than many scientists think. The new research is based on the experiments from the Viking Mars Landers in the late 1970s. The experiments were designed to focus on metabolic signatures, which are chemicals produced by living organisms. Although they found some interesting chemical signatures, they deemed the results inconclusive in 1976.
The same scientists worked on a new study, which reexamined data collected during the Viking experiments in conjunction with recent results from other missions that explored water, methane, and other organic compounds. They concluded that non-biological explanations for the Viking data didn’t satisfy their questions, but that the biological hypothesis is still strong.
During the experiments, they used Martian soil that was injected with a drop of diluted nutrient solution that included a radioactive carbon isotope. The air above the samples was closely watched, and the researchers were able to detect the radioactive isotope in the carbon dioxide from the samples. However, when the results were repeated a week later, they couldn’t find the same signature. Basically, this indicates that the chemical reaction didn’t depend on a living organism.
This suggests that there is an oxidizing agent that’s turning the compounds into carbon dioxide. Peroxide-modified titanium dioxide produces similar results to the findings of the Viking landers, which means that the possibility for life on Mars has to be strongly considered. Even if the experiments don’t provide the proof you need, the finds don’t lie. There still isn’t any definitive proof of life existing on the Red Planet, but the possibility isn’t questionable.
“Even if one is not convinced that the Viking Labeled Release results give strong evidence for life on Mars, this paper clearly shows that the possibility must be considered,” explains Chris McKay, Senior Editor of Astrobiology and an astrobiologist with NASA Ames Research Center in Moffett Field, California in a statement.
Microbial life isn’t the life that comes to mind when we think of alien encounters, but it’s life nonetheless. It’s a major step in the right direction when it comes to answering questions the Red Planet inspires us to ask. Humans will always search for other lifeforms throughout the universe, and if there’s even a small possibility that we could find some on our red neighbor, we have to look.