#earlyearth

#earlyearth

Early Earth was Regularly Hit by City-Sized AsteroidsScientists know that early Earth was bombarded by meteor strikes, but new analysis revealed that the number of those impacts were actually much, much higher than originally thought.The size of the meteor was also much larger - some are city-sized asteroid, with estimated size of more than 10-km wide."We have developed a new impact flux model and compared with a statistical analysis of ancient spherule layer data. With this approach, we found that current models of Earth’s early bombardment severely underestimate the number of known impacts, as recorded by spherule layers", said Physicist Simone Marchi of the Southwest Research Institute in Boulder, Colorado."The true impact flux could have been up to a factor of 10 times higher than previously thought in the period between 3.5 and 2.5 billion years ago. This means that in that early period, we were probably being hit by a Chicxulub-sized impact on average every 15 million years. Quite a spectacle!"The Chicxulub impact was caused by a 10 km (6.2 miles) diameter asteroid, and was thought to cause a mass extinction of 75% of plant and animal species on Earth, including all non-avian dinosaurs.Via EurekAlertImage: Meteor Crater in Arizona, which was the result of an impact of a 50 meter (164 feet) meteor, by Dr Dale Nations/AZGS.#meteor #asteroid #massextinction #meteorite #EarlyEarth #ChicxulubImpact