The mysteries surrounding the dinosaurs entice our imaginations. These magnificent creatures dominated the biosphere of our planet for over 150 million years, then came to an end 65 million years ago, with the close of the Cretaceous period in Earth's history. Those of us who believe in catastrophism, or abrupt change, as I do, over uniformitarianism, or gradual change, as an explanation for the end of the Cretaceous period, embrace the idea that a key player in this mystery came from outer space. The ensuing catastrophic event produced such a dramatic change in Earth's environment that over 50 percent of the species living at the time, including the dinosaurs, perished.
Iridium is rare on Earth's surface, but common in solar system objects such as asteroids and comets.
As intriguing as this evidence was, scientists favoring an extraterrestrial culprit were left without the proverbial smoking gun to clinch the case. Mexican scientists are now carrying out such a program on a limited basis. If this blanket was found on the surface, there would be no immediate need to drill. That expedition proved fruitful. Among the discoveries of our team of Society members and professional geologists was a new species of crab, named Carcineretes planetarius after The Planetary Society.