Arid and devoid of bacteria, the soil in the Atacama Desert (Chile), one of the oldest and driest deserts in the world, closely resembles the red, rocky soil found on Mars. This discovery could enhance our understanding of the experiments conducted on Mars by the Viking spacecraft in the 1970s, and it reignites our hopes for the exploration of the Red Planet.
In 1976, the world was abuzz when the robotic Viking spacecraft made its historic landing on Mars. The biological experiments conducted by Viking revealed unusual signs in the soil’s activity on the Red Planet, resembling gases emitted by bacteria. This sparked excitement among scientists about the possibility of finding life on Mars.
Before announcing findings on extraterrestrial life, the National Aeronautics and Space Administration (NASA) conducted further tests to seek evidence of organic matter on Mars. However, the Viking spacecraft was unable to detect carbon, a fundamental element for the existence of life. Consequently, they were forced to declare Mars a dead planet. Many, however, disagreed with this conclusion and called for continued research.
Now, research efforts have resumed, but instead of Mars, they are taking place in the Atacama Desert. In some respects, the debate surrounding the Viking mission has quieted, but new questions have emerged. Dr. Richard Quinn from NASA’s Ames Research Center stated: “Typically, people assume that the soil activity on Mars is chemical rather than biological. We have identified a location on Earth with a chemical process similar to that on Mars: it restrains life.”
The soil in the central Atacama Desert is extremely dry. The driest areas here closely resemble the regions that the Viking surveyed on Mars. With little water and abundant sunshine, the environment creates a chemical cycle that decomposes organic matter and inhibits life. When replicating Viking’s experiments with soil from the Atacama Desert, scientists received results similar to those from Martian soil.
However, they found traces of organic matter, although at levels much lower than what Viking detected on Mars. The research team concluded that organic matter is always present, but at such low levels that it is difficult to detect. Dr. Quinn remarked: “We have not yet determined whether Viking was unable to detect organic compounds on Mars. Our work suggests that this is entirely possible. However, we will conduct further tests on Mars to answer this question.”
The soil in the Atacama Desert is particularly suitable for testing research equipment intended for use on Mars. Currently, two new devices are being developed, including one for studying chemical processes and another for detecting organic compounds on Mars. Dr. Quinn added: “We hope to use these devices to search for life on the Red Planet.“
