The time is now to prepare for the cosmic object that could spell our end.
Paul M. Sutter | NAUTILUS
Humanity lives on the edge of disaster. The celestial sphere, suspended and serene above us, has guided our species for millennia, serving as a source of stories, wonder, and navigation. But the sky is also full of threats. Asteroids, comets, and meteoroids, traveling at tens of thousands of miles per hour, completely silent and nearly invisible, crisscross the solar system and the orbit of the Earth. When the smallest ones, no bigger than a grain of sand, enter our atmosphere, we watch in delight as a shooting star flies across the heavens.
But when the larger objects strike, they unleash not marvels, but death and destruction. When an asteroid several miles wide struck off the northern coast of the Yucatan peninsula in the Gulf of Mexico 66 million years ago, the resulting impact rattled the Earth to its very iron core, uplifted crustal material and sent it raining hellfire across the globe, plunged our planet into a suffocating “impact winter,” and permanently ended the lineages of all non-avian dinosaurs.
The rate of an asteroid larger than 3 miles across striking the Earth is approximately once every 6 million years.
More recently, some 50,000 years ago, a meteorite about 160 feet across (less than half the length of a football field) struck Earth with a velocity of 29,000 miles per hour. The energy released in the collision was equivalent to 600 Hiroshima bombs. Among other cataclysmic effects, the impact could be felt in the form of a 1,000-mph wind blast more than two miles from the site. The crater today, just east of Flagstaff, Arizona, is roughly 560 feet deep and three quarters of a mile across.
With just a few thousand feet of orbital misfortune, we could lose a population center at a level unheard of even after the advent of nuclear weapons. We could see the collapse of not just one, but all human civilization, and possibly the extinction of our species—or even all the species on the planet. In short, it would be really, really bad.
A substantial collision is bound to happen again. We don’t know where or when. But it will happen. Are we ready? No. Not in the slightest. But for the first time in the planet’s history, we have arrived at a point in time where we could do something to alter its astronomical fate.
The question is whether we will. Yes, we are capable of long-term planning. Medieval Europeans spent centuries building their great cathedrals. Ancient Chinese empires spent generations expanding irrigation networks, many of which are still used today. For tens of thousands of years nations of all stripes have spent decades and untold resources—and the blood of their populace—in evolving combat against their enemies. But these projects have had a tangible, immediate, and familiar feel to them. The threat posed by asteroids and comets is a whole other story. (We also aren’t doing so well with nebulous threats of climate change and zoonotic diseases.)
Brights - Die Natur des Zweifels 