Everyone’s familiar with the demise of the dinosaurs thanks to a massive asteroid that slammed into the earth, causing an extension of most species on the planet. What many may not know is another massive meteorite impacted the planet. That second impact happened about 65 million years ago in what is now Ukraine.
Scientists have ruled out that the second impact contributed to the extinction of the dinosaurs, but the impact does offer insight into the climate history of Earth. Geologists from the University of Glasgow used state-of-the-art dating techniques on samples of melted rock created during the impact of the giant meteorite in what’s known as Ukraine’s Kivorohad Oblast region.
The meteorite collision with the earth created a gigantic 15-mile wide basin known as the Boltysh impact crater, which filled with water over time and became a lake. Decades ago, scientists took samples from the crater that suggested the meteorite impacted between 2000 and 5000 years before the massive strike in Mexico’s Yucatán Peninsula that ultimately killed the dinosaurs. Some believed that the Boltysh impact could’ve occurred in close enough proximity to the Chicxulub impact to have contributed to the extinction of the dinosaurs.
The new study finds that the Ukrainian impact happened about 650,000 years after the Chicxulub event. As a result of the study, the findings could help better understand how the atmosphere responded to climate change in the past. Researchers selected four samples from two rock cores taken from the impact crater in the Ukraine containing rocks generated during impact and lake sediments accumulating over time after the crater was formed.
The age of the samples was determined using argon-argon dating, which measures the radioactive decay of potassium to argon. That decay is known as a “rock clock” ticking down over geological timescales allowing researchers to determine when the rocks were created. The analysis shows the impact occurred very close to 65.39 million years ago, putting it firmly after the Mexican impact that killed the dinosaurs.