Martian mushrooms, the Wow! signal and other unproven claims of alien life

A Recent study claims to have found evidence of fungal life forms on the Martian surface. These special features are known and were discovered by cameras aboard NASA’s Mars Exploration Rover opportunity, shortly after landing in 2004.

In fact, they are not living organisms at all, but “hematite concretions” – small spherical pieces of the mineral Hematiteand their exact origins are still debated by scientists. Hematite is a compound of iron and oxygen and is commercially important on earth. The spherical rocks on Mars may have been formed by the gradual accumulation of the material in slowly evaporating environments with liquid water. They could also have been produced by volcanic activity.

Either way, they’re not mushrooms. The area around Opportunity’s landing site is littered with them – they can be seen all over the surface and have also been found buried underground and even embedded in rocks.

Petrified worms

These space mushrooms were not the first claim to alien life. On August 7, 1996, then US President Bill Clinton stood on the lawn of the White House and announced the opportunity the scientists had discovered the ancient, fossilized remains of microorganisms in a meteorite recovered from Antarctica in 1984.

The meteorite, ALH 84001is one of the few stones we have from Mars. These were blasted from the surface of the planet by volcanic eruptions or meteorite impacts and probably propelled through space millions of years before landing on Earth.

High resolution scanning electron microscope image of the structures NASA

The tiny structures discovered with powerful microscopes resemble microscopic worm-like organisms and are likely billions of years old. The debate about the true origins of these structures continues to this day – many scientists have pointed out that known inorganic processes are quite capable of producing structures that are similar living organisms. In other words, just because something might look a bit like life (mushrooms or otherwise) doesn’t mean it is.

Mystery gases

In the 1970s NASA Vikings Robotic landers conducted a series of experiments to test the Martian soil for the presence of microorganisms.

The experiments chemically treated small samples of Martian soil in reaction chambers on board the lander. in the one of themNutrients containing radioactive carbon-14 were added to the soil samples. In theory, this should be absorbed by growing and multiplying microbes. The carbon-14 would then be increasingly “exhaled” over time, indicating a steady increase in concentration in the reaction chamber.

After the chemical analyzes, each soil sample was steadily heated to hundreds of degrees in order to destroy microbes with the intention of seeing if such reactions in the soil stopped. Interestingly, this particular experiment showed a steady increase in carbon-14 over time that actually stopped after heating to above the boiling point of water. Several inorganic chemical reactions have been suggested to explain this. These results therefore remain inconclusive, and still are discussed today.

More recently minute Amounts of methane were found in the Martian atmosphere. This is also fascinating as living organisms on Earth are known to release methane. However, it must be emphasized again that this is not conclusive evidence of life. Methane can also be produced by various inorganic processes, including through heated rocks.

Impressive!

In 1977 the Big Ear Radio Telescope discovered in the USA an unusual radio signal while scanning the sky. The signal lasted only a few minutes, was very powerful, and was captured over a narrow frequency range. These factors make it quite difficult to imagine a natural cause, as most natural radio sources can be detected over a wide range of frequencies.

The exact signal has not been recognized since then, despite frequent radio surveys of the same part of the sky. The signal was so remarkable at the time that the astronomer on duty, Jerry Ehman, circled the signal printout with a red pen and wrote “Wow!” Besides.

Various explanations have been suggested over the years, including recently that the signal was generated by a passing cometor transmissions from an orbiting satellite. The exact origin of the Wow! The signal is not yet fully agreed today and remains a fascinating puzzle.

Tabby’s Star

A key tool in planet hunting is the dimming method – observing the light of a star to see if it dips regularly when an orbiting planet passes in front of it. In 2015, professional astronomers worked with citizen scientists from the Planet hunter The project announced the discovery of a nearby star that has an unusually strong and even darkening over time.

Tabby’s Star is named after the astronomer Tabitha Boyajian Who was the main author on the Paper announcing the discovery. Data from the Kepler Space Telescope showed not only regular dimming, as one can expect from a planetary orbit, but also very irregular light incursions and, interestingly, a constant decrease in light output over several years.

This highly unusual behavior led numerous theories to explain the observations, including cometary dust or debris from a massive impact that gradually spread and covered the star’s face. Some also speculated that these were signatures of an advanced alien species building a structure around the star. However, further observations have not found confirmatory evidence to support this possibility. For example, have radio telescopes couldn’t see unusual radio emissions from the star. Today the scientists behind the discovery believe that the unusual incursions of light are caused by cosmic clouds of dust walk across the face of the star.

Exciting as they are, it’s important to treat alien life claims with a healthy dose of skepticism, and that’s exactly what scientists do. No conclusive evidence that extraterrestrial life exists has yet been found.

Gareth Dorrian, Postdoctoral fellow in space science, University of Birmingham

This article is republished by The conversation under a Creative Commons license. read this original article.

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