In the vast expanse of our solar system, countless asteroids orbit the sun, most of them harmlessly. However, the possibility exists that one of these space rocks could be on a collision course with Earth, posing an existential threat to our planet and all life upon it. This article explores a hypothetical timeline of events that could unfold if a planet-killer asteroid, measuring 10 kilometers or more in diameter, were to be detected on a path towards Earth.
Initial Detection and Tracking (5-10 years before impact)
The story begins when a NASA-funded observatory discovers a new asteroid, approximately 10 kilometers in diameter, and reports it to the Minor Planet Center. The asteroid is given the designation 2032 PK, and initial orbit calculations by NASA’s Sentry impact monitoring system indicate that it could potentially impact Earth in about 8 years. At this stage, the uncertainty is high, and the impact probability is estimated at around 1%.
Observatories around the world, including amateur astronomers, mobilize to track the asteroid over the coming months, providing additional observations to refine the orbit determination. As more data is gathered, the picture becomes clearer, and after a few months of tracking, the orbit is refined, and the impact probability climbs to a terrifying 100%. The asteroid is definitely on a collision course with Earth, with impact predicted for March 16, 2040.
Assessing the Threat (3-5 years before impact)
With the asteroid’s trajectory confirmed, attention turns to assessing the scale of the threat. Observations indicate that the asteroid is a stony type, likely a chondrite, and is estimated to be between 10-15 kilometers in diameter. An asteroid of this size is large enough to be a global catastrophe, capable of causing widespread destruction and potentially leading to the collapse of civilization as we know it.
Scientists calculate that the impact energy would be equivalent to 100,000 megatons of TNT, making it the largest impact event in the last 66 million years, since the dinosaur-killing Chicxulub impact. The predicted impact location is in the Atlantic Ocean, off the coast of the United States. A water impact of this magnitude would generate massive tsunamis, in addition to other devastating effects.
Preparing for Impact (1-2 years before impact)
As the asteroid hurtles closer to Earth, it becomes clear that deflection is not feasible given the short warning time. The focus shifts to evacuating and preparing the impact zone, as well as bracing for the global consequences. Coastal areas prepare for mega-tsunamis that could reach heights of over 100 meters and travel far inland. Low-lying areas are completely evacuated, and governments begin the daunting task of relocating millions of people.
The public is informed about the impending catastrophe and trained on how to shelter from blast waves, firestorms, and other secondary effects. Emergency supplies, including food, water, and medical equipment, are stockpiled in secure locations. Governments worldwide prepare for an unprecedented humanitarian crisis and the potential for mass casualties. Emergency response and recovery plans are put in place, but the scale of the disaster is almost unimaginable.
Final Approach (last few months before impact)
As the asteroid nears Earth, it becomes visible to the naked eye, appearing brighter than Venus in the night sky. The exact impact point is refined to a location 500 kilometers east of New York City, with impact predicted for 5:30 pm EDT on the fateful day. Evacuations are completed, and all possible preparations are made. The world holds its breath, bracing for the moment of impact.
Impact Day
On the day of impact, the asteroid enters Earth’s atmosphere at a speed of 20 kilometers per second, becoming a brilliant fireball brighter than the sun. It strikes the ocean intact, releasing energy equivalent to 100,000 megatons of TNT. The blast wave reaches New York City in just 4 minutes, flattening structures and causing unimaginable destruction.
The impact blasts a crater 100 kilometers wide into the seafloor, displacing enormous volumes of water and creating mega-tsunamis over 100 meters high that race towards the Atlantic coasts. Seismic waves generated by the impact circle the globe, triggering earthquakes and volcanic eruptions worldwide. Ejecta from the impact rains back down across the hemisphere, igniting wildfires and beginning to form a global cloud of dust that will block sunlight.
Immediate Aftermath (first 24 hours after impact)
In the hours following the impact, massive tsunamis inundate the Atlantic coasts of North America, South America, Africa, and Europe, traveling inland as far as the Appalachian Mountains. Coastal cities are utterly devastated, with millions of lives lost in the blink of an eye. Firestorms rage across the hemisphere as ejecta continues to rain down, igniting anything that will burn. Major cities are destroyed by blast waves and fires, rendering them uninhabitable.
Infrastructure across the affected regions is crippled, with power grids, communication networks, and transportation systems utterly destroyed. Millions are dead, with countless more injured or homeless. Hospitals, already overwhelmed by the injured, begin to run out of supplies. A humanitarian crisis of unprecedented scale begins to unfold, as survivors struggle to find food, water, and shelter amidst the ruins.
Long-Term Aftermath (first year after impact)
As the dust from the impact spreads through the atmosphere, it begins to block sunlight, causing global temperatures to plummet. A years-long impact winter sets in, disrupting weather patterns and causing widespread crop failures. Famine becomes a reality for millions, as food supplies dwindle and distribution networks collapse.
Governments, already stretched to the breaking point by the immediate aftermath, begin to collapse under the weight of the ongoing crisis. Civilization itself starts to break down in many areas, as survivors fight for scarce resources and the rule of law disintegrates. Estimates suggest that between 25-50% of the human population has died from the direct effects of the impact and the cascading disasters that follow.
The road to recovery will be long and arduous, measured in decades rather than years. The world that emerges from the ashes of the impact will be forever changed, shaped by the scars of the worst disaster in human history. The survivors will face the daunting task of rebuilding society, all while grappling with the knowledge that another asteroid could strike at any time.
Summary
This hypothetical timeline serves as a sobering reminder of the devastating potential of a large-scale asteroid impact. While such an event is statistically unlikely, the consequences would be catastrophic on a global scale. It underscores the importance of continued efforts to detect and track potentially hazardous asteroids, providing as much warning time as possible.
With enough notice and preparation, it may be possible to prevent such a catastrophe using deflection techniques, such as kinetic impactors or gravity tractors. However, these methods require significant lead time and international cooperation. In the event that deflection is not possible, having well-developed emergency response and recovery plans in place could help to mitigate the loss of life and ensure the continuity of civilization.
Ultimately, the threat of a planet-killer asteroid impact is a stark reminder of humanity’s vulnerability in the face of cosmic forces. It is a call to action, urging us to work together as a species to protect our planet and ensure our survival. By investing in asteroid detection and mitigation strategies, as well as fostering international collaboration and preparedness, we can reduce the risk of a catastrophic impact and safeguard the future of our world.
