ASTEROID EXPERIENCE

(Spoken by an adult male with a British accent)

Ladies and gentlemen, boys and girls. Welcome to The Asteroid Experience at Expedition Dinosaur: Rise of the Mammals.  Please be aware that The Asteroid Experience will make use of intense sound effects and bright flashing lights. Thank you and enjoy the show. 

One of the greatest illusions in life is continuity. 

Sixty-six million years ago, the continuity of the dinosaurs had been going on for around 165 million years already, and it didn't seem this would change anytime soon. Before the extinction of the dinosaurs, the world was warm and pleasant and most of the land was covered with lush forests and an incredible diversity of trees, flowers, ferns, and trillions of animals. Dinosaurs were ubiquitous and had diversified into hundreds of species of all shapes and sizes. Torosaurus, large gentle giants, shared the world with famous beasts like Tyrannosaurus Rex and Ankylosaurus. Anzu Wyliei hunted in the undergrowth, while Quetzalcoatlus soared over the coastlines and swaps. Imagine an ancient paradise, a world of plenty, teaming with life.

Sixty-six million years ago, maybe on a quiet Thursday afternoon, life was the same as it had been the day before, or a thousand years before, and even a million years before. Everything was good for our feathered dinosaur buddies, until a tiny, tiny detail in the sky changed. If there were any dinosaurs watching the stars, one night, they may have noticed the appearance of a new star.  A strange, tiny dot, that for many weeks would slowly get bigger and brighter each night until it looked like another small moon in the sky. Eventually, this new star would fade from sight as it dipped into Earth's shadow.  For a few more hours, it would seem that the illusion of continuity would be upheld. 

The following morning, the object suddenly appears again., now almost as large and as bright as the sun in the sky, and growing every moment, heading for the coast near the Yucatan peninsula. It takes the asteroid only seconds to pass through the thin layer between space and the ground to make contact, as it enters the atmosphere at almost 60 times the speed of sound.  Larger than Mount Everest, the asteroid reaches from the ocean high into the atmosphere, higher than passenger planes would fly millions of years later. 

At this moment, the world was one way - in a fraction of a second, it would be changed forever. The continuity of the earth… Broken.

As the asteroid hits the shallow ocean and the bedrock below, the energy of billions of nuclear weapons is released all at once. As the asteroid vaporizes, a flash of light illuminates the sky as an eerie bright white sphere grows over the gulf of Mexico. Bedrock melts into seathing hot plasma at tens of thousands of degrees Celsius. The thermal radiation from the explosion travels at the speed of light and immediately burns everything within a radius of about 900 miles while the energy from the impact pushes so hard against earth's crust, that it loses all strength and flows away from the impact site like a liquid, creating a hole 15 miles deep and over 100 miles wide.  The ocean is pushed back for hundreds of miles, just like when a kid jumps into a puddle.  As the crust bounces back, the melted and flowing crust forms a temporary mountain stretching 8 miles into the sky. An incredible amount of material is blasted into the higher atmosphere or even out into space as much as 60 times the original mass of the asteroid. The violence of the strike is felt everywhere on earth within minutes. The magnitude 11 earthquake may be the most powerful quake any living thing has ever experienced in billions of years.  Even on the side of Earth opposite the impact, the ground moved violently by several meters. In the area known today as middle America, any soil vegetation or animal is just shredded into pieces and violently catapulted over a great distance away. Now, the previously displaced oceans return to land as a world-wide ring of tsunamis a half mile in height, enough to cover all skyscrapers humans would ever build. As they crash into the coasts of all continents they drown thousands of miles of coastline. As if matters weren’t bad enough, the conditions on Earth continued to decline.

A lot of the debris from the impact is blasted into space and will orbit earth for thousands of years. Some of it may hit the moon or even Mars but most of it comes right back to the surface of the planet.  As it enters the atmosphere at such speeds, the debris gets very hot - as in hundreds of degrees hot - and this happens to millions of tons of material everywhere around the globe.  This rapidly heats up the atmosphere to astronomical temperatures, hotter than an industrial oven. The heat together with raining debris also likely ignited material on forest floors and sparked wildfires as the earth rotated under the searing hot plume.  Most of the plants and the animals of Earth’s land and oceans would have died very quickly, if they couldn't bury themselves or escape into caves.  Some of them may have lasted for months, as the Earth was transformed into a dark and horrifying version of what it once was. As the day of the impacts draws to an end, many of the dinosaurs are already dead, but the worst is yet to come.

The gigantic plume of vaporized material reached the upper atmosphere and spread around the whole globe. Together with the soot from the burning planet and the aerosols generated at impact, the planet sinks into a deep darkness with only the remaining raging fires illuminating the landscape..  Whatever plants that survived the firestorms will now be starved for sunlight. As global photosynthesis is temporarily shut down. Within days, temperatures crash as much as 25 degrees Celsius. For months and years, the planet will be a hostile, dark, and deadly place. The sudden global winter will last for decades while at least 75% of all species on earth will just vanish from existence. And so, as the day ends, the world is suddenly different.  The continuity that went on for millions of years, is over. The era of the dinosaurs is over, just like that.

Eventually, from the ashes of the old world, survivors emerged. Birds that are the direct descendants of the dinosaurs and mammals like Triisodon and Loxolophus would eventually become the dominant animals on the planet. Without the asteroid, who knows what life on earth would look like today. Without the sudden disruption of continuity that completely changed the planet and all life on it, we might have never had the opportunity to evolve into the species we are today.  

It's not clear how long the human era will last, so far, modern humans have only been around 0.1% of the time the dinosaurs were. And in this short amount of time we've achieved impressive feats from becoming the dominant species of the planet, to splitting the atom and even reaching space. Yet our future and our long-term survival and not a given. If we're not careful it could end in an instant, like the age of the dinosaurs ended. But in contrast to them, we know that our continuity is fragile, even if it doesn't feel like it. We can be prepared and be vigilant and hopeful.  

If we're lucky, our journey will go on for a long, long, time.