Unlike “international terrorism” or “man-made global warming” which are purely human-made concoctions driven by political agendas, the threat of asteroid collisions with the earth is very real, and provides a very serious basis for international cooperation on the common aims and in the interest of humankind.
Anyone see IPAW (International Panel for Asteroid Warning) on the horizon? IPAW scientists, just like IPCC (International Panel on Climate Control) scientists will talk up the threat of asteroid impacts to the point where millions of people will be almost as terrified of imminent asteroid impacts as they already are of global warming and tobacco smoke.
And it will offer new ways of bullying and browbeating millions of people. Because, after all, these people really just want to control other people.
How would IPAW set about bullying everyone?
It’s not too hard to imagine. IPAW scientists would issue asteroid warnings when any new NEOs (Near Earth Objects) were discovered. And as asteroid detection systems improved, there’d be more and more asteroids detected. It would start with one a day, and then rise to 10 a day, and then 100 a day. Anxiety would gradually rise.
People would get notified on their mobile phones of expected impact locations and impact times. There’d be TV asteroid impact warnings just like weather forecasts. People would start checking for impact warnings before travelling anywhere.
Eventually there would be warning sirens just like WW2 air raid warning sirens, and bunkers for people to shelter in. People would be kept off the streets. Anyone found on them would be arrested by armed police.
Whole cities would periodically be evacuated. There would be forced mass movements of peoples from entire regions. All “for their own good”, of course.
See? What a wonderful new opportunity for yet another army of bullies to start pushing people around.
Currently only 8000 of the estimated local asteroids (which are 140 meters or larger) have been identified and nothing is even closely in place to change their trajectories any time soon. Even if a collision were to occur in several years’ time, humanity’s technologies and priorities are dismally far from preventing such a collision. Just to put things in perspective, Bridenstine reminded his audience that in February 2013, a meteor measuring only 20 meters in diameter and travelling at 40 000 mph exploded over Chelyabinsk Russia sending a shockwave that destroyed property and injured over 1600 civilians. The energy in that blast was the equivalent of 30 Hiroshimas. This incident caught the world off guard, since everyone’s eyes were pointed at the other side of the earth where a much larger asteroid came within 17 000 miles but missed that same day.
Nobody saw the Chelyabinsk rock coming. And I suspect that nobody will see the next big impact coming. Or if they see it coming, it will most likely be too late to do anything about it.
There are probably millions of large rocks like Halley’s comet in highly eccentric (highly elliptical) long period orbits around the Sun. Halley’s orbital period is 75 years, but comet Hale-Bopp had an orbital period of 4200 years. Why not comets with orbital periods of 100,000 years? And the longer the orbital period, the higher the impact velocity.
A high speed rifle bullet has a velocity of about 1 km/second. Halley’s comet has a velocity of 55 km/second at perihelion. The extrasolar Oumuamua had a velocity of 88 km/second at perihelion. Supernova ejecta can be a lot faster:
the resulting supernova explosion expels much or all of the stellar material with velocities as much as 10% the speed of light (or approximately 30,000 km/s).
So if a supernova explodes anywhere near the Earth, there’ll be stuff flying out from it at these sorts of velocities.
The star Betelgeuse in Orion is 430 light-years away. And it’s due to explode sometime soon. If it sprays out material moving at 10% of the speed of light, it’ll start showing up 4300 years later.
The Crab Nebula is 6,523 light years away. It’s a supernova that was observed by Chinese astronomers in 1054 AD. So I estimate that Crab Nebula ejecta should start arriving in about 60,000 years time. It takes light about 8 minutes to reach the Earth from the Sun. So something travelling at 10% of the speed of light would traverse the orbit of the Earth in 2 x 80 minutes = 160 minutes, or about 3 hours. Do we have equipment to detect stuff moving at these very high speeds? I very much doubt it.
The Chicxulub asteroid which struck the Earth 65 million years ago, wiping out the dinosaurs, is estimated to have been about 11 km in diameter, and travelling at about 12 km/second. But given that kinetic energy is proportional to the square of velocity, it could have been a 20 metre radius iron sphere moving at a speed of 30,000 km/second. That’s about the same size as the Chelybinsk rock, that nobody saw coming.