A billion-year-old asteroid offers new clues to how life may have begun on Earth

How a billion-year-old asteroid is helping scientists trace the origins of life on Earth (Image: Canva)

• Scientists report that RNA, a key molecule for life, may have formed naturally on early Earth through simple chemical processes. Experiments show borates support RNA formation rather than hinder it. Combined with discoveries of RNA ingredients in asteroid samples from Bennu, the findings suggest life’s building blocks could be common across the universe and may have emerged on Earth surprisingly early.

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Scientists say a key molecule for life may be widespread. New experiments suggest RNA could form naturally. The research focuses on Earth’s earliest chemical conditions. Scientists recreated environments from more than four billion years ago. The findings suggest life’s building blocks formed surprisingly easily. The study was published on Dec. 15. It appeared in the journal Proceedings of the National Academy of Sciences.

RNA plays a central role in living systems. It helps translate genetic information into proteins. RNA stating molecules are simpler than DNA. Scientists believe RNA appeared before DNA. This idea supports the long standing RNA world hypothesis. That theory proposes early life relied entirely on RNA.

How RNA Could Have Formed Naturally

Researchers have long struggled to explain RNA’s origin. The molecule requires precise chemical reactions. Many believed random formation was extremely unlikely. Chemists therefore search for reliable chemical pathways. One such pathway is the Discontinuous Synthesis Model. This model outlines six steps toward RNA formation.

A major obstacle involved borates found in seawater. Borates are negatively charged oxygen boron compounds. Earlier studies suggested borates block key reactions. This made natural RNA formation appear difficult. That assumption is now being questioned.

The research was led by Yuta Hirakawa. He works at Tohoku University in Japan. Scientists from Florida also participated. The team tested RNA ingredients under early Earth conditions. They mixed ribose sugars, phosphates, and nucleobases. Borates and basalt rock were also included.

The mixture was heated and dried repeatedly. Researchers say this mimics ancient underground aquifers. These environments likely existed across early Earth. The result surprised many chemists. RNA formed successfully within the mixture. Borates did not prevent reactions. Instead they supported critical chemical steps.

Why Borates And Space Rocks Matter

Borates helped stabilise fragile ribose molecules. Ribose often breaks down without protection. Borates also aided phosphate formation. These steps are essential for RNA assembly. The findings challenge decades of chemical assumptions.

The study connects with asteroid research as well. NASA’s OSIRIS REx mission returned samples from Bennu. Scientists recently confirmed ribose within those samples. This means all RNA ingredients exist in space rocks. Bennu delivered 120 grams of material. That included stones and fine dust.

Hirakawa’s team proposes a large impact scenario. A massive protoplanet struck early Earth. It measured about 500 kilometres wide. The impact delivered RNA ingredients in bulk. Researchers estimate this happened 4.3 billion years ago.

That timing fits geological evidence. It occurred 200 million years after Earth formed. It also predates the oldest known life evidence. Carbon isotopes in ancient zircon minerals date to 4.1 billion years.

What This Means Beyond Earth

Scientists note similar impacts hit early Mars. RNA ingredients may have reached Mars too. Borates have also been detected there. This suggests RNA could have formed on Mars. RNA itself is not living. However it is essential for life.

If RNA formed quickly, life may arise easily. That possibility extends beyond Earth alone. Researchers stress debate continues around laboratory intervention. Critics argue experimental setup still involves human input.

Despite debate, the findings reshape origin discussions. RNA may not be rare in the universe. The study suggests chemistry naturally favours complexity. Life’s beginnings may have been faster than expected.