The catastrophic collision of two giant asteroids between the orbits of Mars and Jupiter threw out a huge amount of dust into space, which, reaching Earth, polluted the atmosphere of our planet and, preventing the passage of sunlight, provoked or accelerated the onset of the Ordovician ice age.
Philip Heck, a co-author of the study from the University of Chicago said that about 40,000 tons of dust from the space settles on our planet annually, but it is only a tiny fraction of the Earth’s previously contained dust in the atmosphere and does not have climatic significance. Anyway, imagine that a couple of million years after the collision of asteroids, this flow increased in a thousand, or even 10,000 times.
About 466 million years ago, the temperature on Earth gradually began to fall, resulting in a decrease of 10 degrees Celsius. The seas began to be covered with ice at the poles, and the prevailing temperature range, on the one hand, led to a large-scale extinction, during which nearly 60 percent of marine life died, and on the other hand, paved the way for a future boom in the evolution of new species.
Helium Atoms That Came From Cosmic Dust
The reason for this ice age is still a mystery, and to get closer to its solution, scientists turned to 466-million-year-old rocks that once belonged to the seabed, analyzing their chemical composition and comparing it with the reference composition of tiny micrometeorites mined in Antarctica.
The team searched for samples of elements that have almost never been found in terrestrial rocks, as well as isotopes, indicating signs that their carrier had arrived from space. For example, helium atoms usually have two protons, two neutrons, and two electrons, but some of them, wandering in space, have one neutron. The presence of such isotopes in the rocks, along with the rare metals often found in asteroids, proves that they were contaminated with cosmic dust.
Coolings Caused By Cosmic Dust Gave Birth To New Species
According to the study, since dust had been falling on our planet for at least two million years, cooling was gradual enough for life to adapt and even benefit from these changes, producing new species adapted to survive in regions with different temperatures.
However, although this particular period of global cooling has been proved to be somewhat favorable, rapid climate change can be catastrophic.
A Solution To Global Warming
Today, global warming is gaining momentum on Earth as a result of increased carbon dioxide emissions. According to the Intergovernmental Panel on Climate Change, we are approaching a situation that resembles the conditions that existed before the collision of asteroids 466 million years ago.
In the last decade, scientists around the world have been discussing various artificial methods of cooling the Earth in the event of a major climatic catastrophe, and one of the results of the study was the support of an unexpected idea involving the placement of asteroids in the orbit of our planet like satellites that would continuously release fine dust and, therefore, partially blocked the sunlight.
The idea itself is hypothetical, but in the course of Earth’s history, it had phases of cooling under the influence of cosmic dust.