Third Rock Gratitude

Mimas, moon of Saturn

We recently learned about the specatular encounter between us, Earth, and an object from deep space. In our lifetime, this is indeed a remarkable event. Yet, all we need to do is gaze up at the Earth’s moon (or look at photos of other moons in our own solar system) and its surface is pocked with the evidence of innumerable such encounters. In fact, science has overwhelming evidence that a similar but vastly more violent encounter occurred on Earth 65 million years ago. This is referred to as the Chicxulub Crater in an area straddling the present day Gulf of Mexico shoreline north of Mérida. Unlike the reported SUV-sized object that exploded above the Russian Urals on February 15, 2013, this ancient collision was thought to have been the size of Manhattan Island. Scientists believe its devastating effect on global climate caused mass extinctions including those of the dinosaurs. Asteroids and meteoroids are common place in the space environment but we are thankfully protected from most of them by our gas-rich atmosphere. We also are grateful for the astronomers who keep a watchful eye on large objects, say larger than a football field, whose impact with a populated area on Earth would be disastrous. Next time you wish upon a ‘shooting star’, or gaze at our cratered moon, know we are lucky to be living on this protected third rock from the Sun!