The calamity in the asteroid belt sparked an ice age and shaped life in the oceans 466 mins ago: Study- Technology News, Firstpost


The cataclysmic impact of an asteroid off the coast of Mexico that doomed dinosaurs 66 million years ago was not the only time an astronomical event has shaped the history of life on Earth.

Scientists said on Wednesday that dust generated by a gigantic collision in the asteroid belt between Mars and Jupiter 400 million years earlier sparked an ice age on Earth that ushered in a significant increase in marine biodiversity.

The event, which occurred when life was concentrated in the seas and long before vertebrates first moved on land, triggered evolutionary changes in fundamental invertebrates of marine ecosystems as they s were adapting to global cooling, they said.

An artist visualization of asteroids in the solar system. AFP

The inner solar system was filled with huge amounts of dust after an asteroid more than 150 km in diameter was struck by a smaller object about 20 km wide, the researchers said. It is the largest known collapse of the solar system in the past 2 billion years.

Solar radiation reaching the Earth’s surface has been reduced for at least 2 million years by dust in space and the planet’s atmosphere, said study co-author Philipp Heck, curator associated with the Field Museum in Chicago.

Another cooling mechanism was that iron-rich meteor dust fertilized large parts of the ocean surface, resulting in increased plankton productivity and reduced atmospheric carbon dioxide, added Birger Schmitz, professor of geology at Lund University in Sweden and research published in the journal Scientists progress.

“Over the past few decades, researchers have started to understand that the evolution of life on Earth also depends on astronomical events,” Schmitz said.

An ancient mass extinction called the Great Death wiped out 90% of all life on earth.  Image: Earth Archives

An ancient mass extinction called the Great Death wiped out 90% of all life on earth. Image: Earth Archives

After noting the dinosaur disappearance event caused by a 10 km wide asteroid, Schmitz added: “For the first time, scientists can now present another example of how an alien event shaped life on Earth.”

Researchers found traces of dust in sedimentary rocks formed at the time containing special isotopes of helium and rare minerals that revealed its extraterrestrial origin.

Groups of invertebrates that saw diversification included horseshoe crab-like trilobites, clams, clam-like brachiopods, and a group called gastropods that included snails and slugs.

The cooling event unfolded gradually, allowing the Ordovician’s marine life to adapt, unlike the sudden impact that wiped out the dinosaurs. The Earth’s climate has changed from tropical to semi-tropical all over the world to divide into climatic zones as is the case today with frozen poles and tropical conditions at the equator.

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