Sat. Jan 22nd, 2022


Alan Hills 84001 Meteor.

Alan Hills 84001 Meteor.
Pictures: Doug Mills (AP)

The apparent fossils of the Alan Hills 84001 meteorite – a fragment of rock formed on Mars about 4 billion years ago – were produced by water and not microbial Martians, according to new research. But scientists aren’t sure about the original fossil claim.

The 4-billion-year-old fragment formed on Mars during the turbulent Noachian period of the Red Planet was swept into space by a massive impact about 17 million years ago and landed on Earth about 13,000 years ago. Named after the Antarctic Allan Mountain where it was found, the 4.3-pound (1.94 kg) meteorite is one of the oldest meteors ever recovered.

A team of NASA-led scientists took the world by surprise in 1996 Advice In that meteorite, worm-like carbonate globules were fossils, and so the first evidence of alien life. Many scientists have questioned this explanation, citing so-called “biomorphs” as well as other theories such as volcanic activity, impact events, and exposure to water. Most scientists agree that there is no evidence of life in ALH84001, but the controversy continues for more than a quarter of a century.

Electron microscopy revealed insect-like properties in meteorites.

Electron microscopy revealed insect-like properties in meteorites.
Pictures: NASA

The last chapter of this story appeared on Thursday – a new one Paper In science that again makes the case for abiotic processes as responsible for the properties seen in meteorites. The new paper specifically argues that the organic molecules found in meteorites are formed from slow and steady interactions as groundwater moves through cracked rocks. From Astrobiologist Andrew Steele Carnegie Institution for Science Led new research.

Now, to describe something as “organic” does not mean that it has anything to do with life. Organic molecules are usually composed of carbon and hydrogen and sometimes oxygen, nitrogen and sulfur. Of course, these molecules are often associated with biological processes, but they can also be derived from abiotic processes, known as abiotic biochemistry.

Regarding the relevance of the new study, the new paper reminds us that “Mars rovers have found complex organic molecules in the ancient rocks exposed to the surface of the planet and methane in the modern atmosphere.” “It’s not clear what processes these organisms created, including proposals for both biotic and abiotic sources.” It analyzes the source of minerals in ALH84001 that the team sought to better understand “the geochemical processes that took place early in the history of the earth and the potential for habitation on Mars.” Steele, a member of NASA’s Perseverance and Curiosity team, explained in a Carnegie Press release.

In fact, the new study is more than an attempt to disprove the claim that ALH84001 contains Mars fossils. This study also talks about the early stages of Mars and Earth, how these conditions probably formed the basis of the origin of life and why the features we see on Mars today, such as the presence of methane. “The search for life on Mars is only ‘Are we alone?’ Not trying to answer the question, “said Steele. “It has to do with the early Earth’s environment and ‘Where did we come from?'”

Steele and his colleagues used nanoscale microscopic imaging, spectroscopy, and an isotopic analysis to study the meteorite, concluding that the organic molecules were formed as a result of interactions between water, possibly salt water and basalt rocks.

The paper states that one of the two possible geochemical processes was responsible for biosynthesis: serpentineization and carbonization. In serpentineization, volcanic rocks rich in iron or magnesium interact with the conducting water, resulting in the formation of hydrogen and in carbonization, the acidic water with dissolved carbon dioxide reacts with the rock, resulting in carbonate.

Scientists say it is not clear which of the two is responsible or the exact sequence of events, but they say it has been around for a long time, the reaction has produced organic from carbon dioxide depletion and is abiotic. The process alone Was responsible for carbon-rich compounds.

Scientists behind the 1996 study weren’t impressed with the new paper, such as The Guardian Report. They say it Does not offer anything new and the explanation is not supported by any evidence, adding that “[u]n Supported hypotheses do nothing to solve the problem surrounding the origin of organic matter in meteorites.

So the debate peaked. But tIt will not be a single rock Answer the question of whether life once existed on Mars or still exists. For that, our best current option is a sample return mission, which fortunately is already underway. NASA’s diligent rover is currently collecting and storing surface samples for a future mission On Earth, probably in the early 2030s.

More: Scientists only need to follow these 7 steps to prove the existence of aliens.



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