(ORDO NEWS) — Comets visit the inner solar system and leave without saying goodbye. Maybe they leave a trail of dust behind them, and when the Earth passes through it, we get a beautiful light show in the night sky, in the form of a meteor shower.
Sometimes these rocky aliens head straight for Earth. And when they do, the results can be disastrous, for example, when an asteroid struck Earth about 66 million years ago, it wiped out dinosaurs and 75% of life on Earth. In other cases, it is not nearly as disastrous, but still destructive as it was in about 2350 BC, when the debris of a decaying comet may have caused the collapse of an ancient empire.
The rocks are large enough to leave massive craters, and although the earth is good at erasing these craters, scientists still find them, as evidenced by the discovery of the impact crater of the Chicxulub meteorite that ended the dinosaurs.
But what about tiny ancient micrometeorites? Don’t they have anything to tell, too? Of course have!
Since about 1990, Professor Schmitz has been looking for micrometeorite impact fossils and started in a limestone quarry in Sweden. This quarry produces floor blocks and when workers find dark spots in it, they throw them into the garbage area of the quarry. But, as it turned out, these “spots” indicate micrometeorites that hit the earth about 470 million years ago. Professor Schmitz co-authored a research paper on these micrometeorites in 2016.
Now, when workers in the quarry find blocks that appear to contain micrometeorite, they warn Professor Schmitz. About four or five times a year, they find such blocks with a black spot several centimeters across. Initially, Schmitz believed that these types of fossilized meteorites might be present in other quarries, but as it turns out, the Swedish quarry is special.
The sediment, which eventually becomes limestone, must slowly accumulate at the bottom of the reservoir over a long period of time. This allows more micrometeorites to be embedded in it. After 10 years of collecting micrometeorite fossils from the quarry, Schmitz had about 50 of them.
Professor Schmitz and his colleagues published an article in 2004 showing that these micrometeorites were not exposed to prolonged exposure in space. According to their research, micrometeorites have been in space for just a million years, which in the astronomical sense is not so much. Proof of this was the effect of cosmic rays on the mineralogy of micrometeorite fossils.
In this article, the authors wrote that “very large collisions in the asteroid belt could temporarily lead to a significant increase in the frequency of meteorites falling to Earth. They also concluded that” fossil meteorites in southern Sweden probably originate from the inner main asteroid belt. ”
Exploring these tiny fossils may seem like a far cry from things like the Chicxulub encounter that wiped out the dinosaurs. But the plot of the story contains more than just a climax. Throughout its journey, the Earth has been shaped by events such as asteroid collisions and the resulting shower of micrometeorites.
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