What role have meteors and asteroids played in climate change?
Scientists have long suspected giant meteorite impacts have had a significant impact on the Earth’s climate and ecology. Currently they have identified about 110 preserved meteor impact craters on our planet’s surface, some of which date back as far as 600 million years. Two very large craters located in Canada and South Africa may trace their origins back to impacts two billion years ago. Catastrophic changes in the Earth’s climate system due to an asteroid impact in Mexico’s Yucatan Peninsula 65 million years ago perhaps led to the extinction of the dinosaurs. Now research suggests that the constant pummeling of the planet from above during much earlier times may also have played a role in continental drift, giving the continental plates an extra shove, so to speak.
Analysis of dust in cores drilled in the sea floor bottom near the Azores suggests that our planet intercepts a blob of cosmic dust about every 100,000 years. Exactly how that might influence climate, however, is anything but clear. There may be a closer link between the stars and the human race than once thought, but not in an astrological sense. When stars explode in giant super novas, cosmic ray radiation causes the element beryllium-10 to be formed in our atmosphere. The traces of one such massive super nova about 35,000 years ago can be found as enhanced beryllium concentrations buried deep in the polar ice caps. Some speculate that the radiation bombardment could have sharply increased mutations in many life forms, speeding up the human evolutionary process.