I implore you to join me on a thought experiment pertaining to the end of life on Earth. You may believe this to be depressing after that first sentence, but I assure you this is simply an exercise in thinking about the end of the world. I will ask you to consider the end of the world by way of astronomical object colliding with the Earth.

The comet proposed as the cause of the extinction of the dinosaurs would have been around ten miles in diameter. For a size reference, imagine an object about the size of a small suburb. We need to think about an object that size impacting the Earth.

The first thing to happen in this catastrophe would be the carnage caused by the initial impact. Although a mere ten miles across, the crater would be roughly one hundred fifty miles across. This isn’t an exact answer, but you can see that the size of the crater is multiplied several times over. This is caused by the energy of motion of this traveling rock being converted into seismic energy (among other types) of the Earth. I hope this statement isn’t needed, but any life in this radius has almost zero chance of survival.

That is stage one of the catastrophe

The second catastrophic event would be the earthquakes to follow the impact. The largest impact ever recorded was magnitude 9.5. The 9.5 magnitude event was powerful enough to cause devastation for a thousand miles around the epicenter. That is very dangerous.

The earthquakes caused by our comet would be roughly magnitude twelve to fifteen. This would have the power to create a fault around the entire planet. The shifting of the ground due to the quake would be upwards of twenty-five feet. This would cause a huge amount of ground damage. This is where most life ends.

The only means of surviving these quakes would be to live on the exact opposite side of the Earth as the impact. As for an explanation, the Earth’s core is nearly impenetrable to seismic activity. If any of the shock wave did manage to go through, the tremors would be much more survivable.

Now that eighty percent of the world is in complete devastation, what happens to the other twenty percent?

This is the last and final stage of the catastrophe. I call this one Armageddon.

I didn’t tell you the entire story. When the comet enters the atmosphere, it creates a hole in it. That hole in the atmosphere closes in a very short timescale, but it is open for a very small time.

It just so happens this time is long enough for dust, debris, and other particles from the impact to rise up into the highest layers of the atmosphere. It doesn’t sound to bad does it?

Wrong. This is the world ender. The dust and debris travels through the atmosphere around the world. The particles are heavy enough that they will not stay suspended in the atmosphere. This means they will reenter and fall towards Earth.

Most people have heard of celestial rocks entering our atmosphere. What happens to them? These rocks heat up and melt in the atmosphere before ever coming close to the planet’s surface.

So how does this pertain to our debris? Well, it also heats up in the atmosphere. The heat energy imparted into the atmosphere is quite magnificent. It is enough to raise the temperature of the Earth high enough to cause anything combustible to ignite. Anything not covered in water will burn.

So what does this mean for the surviving life on Earth? They countdown the time until everything around them burns.

At twenty minutes after impact, the third of the world closest to the impact is on fire.

After forty minutes, the closest two thirds of the world are burning.

One hour after impact sees the entire Earth engulfed in flames. This is insurance of the extermination of all life.

I will offer you the benefit of the doubt and assume someone survived this carnage. That group of people is welcomed into a world of nothing. The oxygen in the atmosphere has been expended in the burning of the world.

There is nothing to eat. There is no shelter. There is nothing to breathe. There is no life.