The crash of a huge asteroid caused an ice age on Earth, but it also gave life momentum

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(CNN) - Earth experienced an ice age 466 million years ago when a giant asteroid fragmented and sent dust waves to our planet for the next 2 million years, according to a new study. And surprisingly, while the massive influx of dust caused global temperatures on Earth to plummet, it also provided the opportunity for new evolving species to flourish.

The 93-mile-wide (149-kilometer) object was in the asteroid belt located between Mars and Jupiter when it collided with something else and fragmented, creating a large amount of dust that flooded the inner solar system.

• An asteroid with the power of 10 billion atomic bombs from World War II may have annihilated the dinosaurs

"It's analogous to standing in the middle of the living room and breaking a vacuum bag, only on a much larger scale," said Birger Schmitz, lead author of the study and professor of geology at Lund University.

Meteorite fragments were analyzed and it was determined that their origin is the asteroid event that occurred 466 million years ago.

Earth is no stranger to the entry of space material, such as parts of comets and asteroids.

"Normally, Earth receives about 40,000 tons of extraterrestrial material every year," said Philipp Heck, author of the study, curator of the Field Museum and associate professor at the University of Chicago. "Imagine multiplying that by a factor of 1,000 or 10,000."

To put that in perspective, let's think of cargo trucks with interplanetary dust. Over the course of a year, the Earth receives as much dust as to load 1,000 trucks.

But during the 2 million years after the fracture of the huge asteroid, Earth was flooded with the dust of 10 million trucks.

"Our hypothesis is that large amounts of extraterrestrial dust over a period of at least two million years played an important role in changing the Earth's climate, contributing to cooling," said Heck.

The study was published Wednesday in the journal Science Advances.

The asteroid dust caused a disruption in the amount of sunlight the Earth received, which led to an ice age. This really set the stage for the conditions we now see on Earth: Arctic conditions at the North and South poles and more tropical conditions around the equator.

Before this ice age, the weather on Earth was more similar worldwide, not divided into climatic zones.

Trilobite fossils that evolved after the ice age of the mid-Ordovic period.

But these climatic zones also provided a way for Earth's invertebrates to adapt to new conditions and temperatures. These adaptations led to a "boom" in evolution.

"In the global cooling we study, we are talking about time scales of millions of years," said Heck. “It's very different from the climate change caused by the meteorite that killed the dinosaurs 65 million years ago, and is different from today's global warming: this global cooling was a slight push. There was less stress. ”

To understand how this process developed, the researchers found evidence of space dust enclosed in rocks of 466 million years that were once at the bottom of the sea. These were compared with micrometeorites that have recovered in Antarctica. The researchers knew, according to previous studies, that an ice age had occurred at that time.

Space dust recovered from the rocks by treating them with acid that can dissolve the stone, but not extraterrestrial matter. They also found in the rocks elements and different forms of atoms that indicate an origin in space, rather than on Earth. They discovered special helium atoms that lack a neutron, which means they originated in the Sun, as well as rare metals that are usually found in asteroids.

The rocks also indicate that the oceans were more shallow at that time, probably because the water was trapped in the ice.

Together, the researchers have evidence of an influx of space dust trapped in fossilized rock, as well as indications of an ice age dating from the same time, linking cause and effect.

"Our results show for the first time that, on occasion, such dust has dramatically cooled the Earth," said Schmitz.

The discovery occurs when the Earth faces climate change again. But could placing asteroids in orbit around our planet help stop global warming?

"Geoengineering proposals should be evaluated very critically and carefully, because if something goes wrong, things could get worse than before," said Heck. “We are experiencing global warming, it is undeniable. And we have to think about how we can prevent catastrophic consequences or minimize them. Any idea that is reasonable must be explored. ”

Asteroids