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| Fossil of trilobite that evolved following the mid-Ordovician ice age. | Birger Schmitz |
Topics: Asteroids, Astronomy, Biology, Planetary Science
Tyche: Modern Greek: [ˈti.çi] "luck"; Roman equivalent: Fortuna) was the presiding tutelary deity who governed the fortune and prosperity of a city, its destiny. In Classical Greek mythology, she is the daughter of Aphrodite and Zeus or Hermes. Source: Wikipedia
Dust from the breakup of a 150-kilometer- (93 mile) diameter asteroid may have caused — or at least intensified — an ice age half a billion years ago, providing the impetus for a sweeping array of aquatic animal adaptations that shaped today's spectacularly diverse ocean ecosystems, according to a new study published in the September 20 issue of Science Advances.
The authors uncovered extraterrestrial material in sediments that correlate the timing of asteroid breakup with a major dip in sea level frequently attributed to the onset of the Mid-Ordovician ice age. Their findings suggest that asteroid dust may have settled in Earth's atmosphere, shading the planet from the sun's radiation and cooling global temperatures.
While extraterrestrial dust only accounts for about one percent of the modern atmosphere and does not impact the climate, large quantities of dust lingering for several hundred thousand years or more would be expected to cause global cooling.
"This is the first time anyone has shown that asteroid breakups and asteroid dust can lead to ice ages," said Birger Schmitz, a professor of geology at Lund University in Sweden and the first author of the study. "This is also the first time since the discovery of the asteroid impact that killed the dinosaurs that an important event in the history of life has been tied to an astronomical event."
Asteroid Dust May Have Triggered Ice Age and Sea Life Explosion
Shannon Kelleher, American Association for the Advancement of Science
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