49 years ago, NASA's equipment may have unintentionally wiped out life on Mars. Here's why scientists believe this happened (photo included).

In 1975, NASA's spacecraft "Viking 1" entered orbit around Mars to conduct a detailed study of the Red Planet. Shortly thereafter, it dispatched two landers to the Martian surface, which became known as the first U.S. spacecraft to land on the Red Planet. The authors of a study published in the journal Nature Astronomy believe that these landers inadvertently eradicated extraterrestrial life on Mars. How did this happen? This is discussed by Space.

The NASA landers collected soil samples on Mars and analyzed them using onboard laboratories. However, scientists knew very little about the environmental conditions on Mars almost 50 years ago. Hence, the method for detecting potential microbial extraterrestrial life on the Red Planet was developed based on techniques used for identifying microbes on Earth.

The NASA spacecraft added water and nutrients to the soil samples and searched for any signs that might indicate the existence of Martian microbes. These signs were related to the microbes' reactions to the introduced water and substances.

As a result, both NASA landers transmitted information back to Earth that they had found extraterrestrial microbial life on Mars. However, further investigations led most scientists to conclude that, in fact, no life was discovered on the Red Planet, and there are alternative explanations for the obtained results.

At the same time, the authors of the new study believe that the NASA spacecraft may have indeed detected life on Mars. But the method used to search for this life inadvertently led to the extinction of Martian microbes.

Scientists believe that because Mars is drier than even the driest places on Earth, Martian microbes, like Earth microbes in similar conditions, obtain water through salts that draw moisture from the atmosphere. Therefore, any Martian life is highly sensitive to the addition of liquid water. Just one extra drop could threaten their existence. At least this is certainly true for Earth microbes that inhabit very dry conditions. But scientists believe that the same applies to Martian life.

According to scientists, Martian life needs water, just like most life forms on Earth. However, as a result of NASA's investigations, too much water was added. Therefore, the landers may have detected extraterrestrial life on Mars, but then inadvertently killed it.

The authors of the study compare NASA's experiments on Mars in the search for extraterrestrial life to a scenario where aliens arrived on Earth and saw a human in the desert. Given that humans are mostly made up of water, the aliens might have thrown the person into the ocean to save them. How long could that person survive in the open ocean? Most likely not long, and something similar may have happened to the Martian microbes that found themselves in a comparable situation.

Thus, scientists believe that the search for life on Mars should focus not on areas with water, but rather on those with salts. Martian microbes may have adapted to drastic changes in the Martian environment, as it is believed that this planet resembled Earth somewhat billions of years ago. There was a lot of liquid water on the surface and it was much warmer than it is now.

The authors of the study suggest that the most promising locations for searching for Martian microbes are soils containing salts such as sodium chloride, chlorates, and perchlorates. These salts may provide a more suitable habitat for microbial life.

Additionally, scientists emphasize the need to employ various methods for searching for potential life on Mars, as it may differ from life on Earth.