On the other hand a reentering ICBM warhead (test) looks like from the ground as if the gods are angry with you and your general vicinity: https://www.youtube.com/watch?v=2a1acYZ93yc
The larger it is, the longer it will stay hoovering and only slowly growing in size.
A city-sized asteroid wouldn't be more than a bright dot until the last seconds before entry, and at interstellar speeds it would take about three seconds to go from the vacuum of space to ground impact unless it had a very shallow vector.
also, seen by who/what? for the only known living things that could see it, it would be the last thing they did see. so maybe as far away as a couple of inches?
I love how they use this mechanic for storytelling in "The Expanse". The rebels of the belt threaten earth by slinging rocks at it at really high speed. Seems a very realistic way of interplanetary war. Why not bend some fast moving rocks to your enemy?
I decided to challenge the glorified-autocorrect machine with some more-manual napkin math, and I get 5.56×10^13 megatons, which is smaller by a factor of ~786x.
That discrepancy is too big to explain just in terms of asteroid composition: Even an impactor of pure Osmium would only be ~12x more energetic.
Here's my work, if anyone wants to check for errors:
Asteroid volume 1 km³
Asteroid density 1 2 grams / cm³ https://en.wikipedia.org/wiki/Standard_asteroid_physical_characteristics
Volume conversion 1E+15 cm³ / km³
Asteroid density 2 2E+15 grams / km3
Asteroid mass 2E+15 grams
Asteroid velocity 0.9 c
Relativistic kinetic energy 2.33E+29 joules https://www.omnicalculator.com/physics/relativistic-ke
TNT energy 4.18E+03 joules/gram
TNT mass equivalent 1 5.56E+25 grams
Mass conversion 1.00E+12 grams per megaton
TNT mass equivalent 2 5.56E+13 megatonsHehe, I too love vacuuming.
Edit: added /s for those unable
I suppose you capitalise aspirin as well.
YouTube has shown people real big explosions (Beirut, Tianjin, etc) and how vicious they are, but you rarely see a CGI shock wave.
Rockets too, RPGs are fast but movies have them sauntering through the air.
however, that's because its trajectory was nearly horizontal rather than nearly vertical, so most of the people who saw it and were injured by it were tens of kilometers away, and it broke apart (exploded really) at 30 km up. it was initially traveling 19 km per second, 2½ times leo orbital speed. if you're traveling 19 km per second vertically instead of horizontally you only have 5 seconds from the von karman line (100km) until you make a crater or a tunguska
3 seconds from visibility to devastation still might be enough for hollywood dramatic flair
As a short-range interceptor, Sprints were slammed up out of their silos via an explosively-driven piston, then they would ignite and reorient in midair, accelerating at 100g to reach Mach 10. The missile itself couldn't see very much, but would be remotely guided with strong signals from the launch installation.
https://www.youtube.com/watch?v=gSFIkGfbLxs&t=23m37s
On a more scientific note, here's a video from the Space Shuttle boosters as they reenter (2005): https://youtu.be/527fb3-UZGo?t=70
So let's say your spies are telling you that the enemy can deliver 60 kiloton device with 200m circular error probable (CEP). Then your engineers can calculate how likely is that your bunker/silo will survive that (and can do something like a counter attack.)
And you build the number of silos you think you need based on that calculation. You put a lot of concrete and lot of work literally in the ground based on those numbers. And then suddenly your enemy just improves their guidance system and they drop (figuratively) such a video on you. That tends to cause jitters.
I'm also talking about the LGM-118 Peacekeeper missile system. It was in service from 1986 to 2005. Did it ever needed to be used in anger or not? During that time did any military attack the nation which fielded it?
If not I would say it lived up to its name.
The US nuclear program is about deterrence after all. Well, after 1945, anyway.
These comments are being obtuse on purpose. Look at the name and look at what the name is on. The name peacekeeper is on a weapon that will only be used in times of no peace. Not a hard thing to see the irony in.
In my view, violence, or hopefully, just the threat of violence, maintains order.
There are certain classes of people where diplomacy and pacifism just isn't going to work.
Again, the post-1945 US nuclear program is about deterrence ("peace through superior firepower"). So, in that perspective, the Peacekeeper's threat of violence... kept the peace.
The US and the Soviet Union/Russia both do not want to use nuclear weapons.
Citation: Self. Was in the nuclear program during the latter days of the Cold War and shortly thereafter.
Which, you know, is the dice we're going to be rolling from now on. Maybe we'll survive the next century, then maybe the next, but in the long term? Humans just don't have that good judgement.
It is indeed a deadly weapon system. But it is used every second during peacetime too. Every second it is fielded it maintains a situation where the preferable choice of action is to not attack the one fielding it. In other words it is keeping the peace.
The name "peacekeeper" is a formal acknowledgement of its purpose in the military arsenal. It has no other role.
If you want peace, prepare for war.
Or as Roosevelt put it, speak softly and carry a big stick.
Building an incredibly powerful weapon and calling it "Peacekeeper" is meant to strongly imply that we don't plan on using it, but rather, it's symbolic as a preemptive threat against any would-be attackers. Peace is kept by showing that any attack would be retaliated with overwhelming force.
What else does maintain peace besides power?
The strong do what they can, the weak suffer what they must. If you want peace prepare for war. Do you think these are just famous slogans or they really do reflect some hard earned wisdom?
Would we still have an equivalent war deterrent today without nuclear? What would it look like?
My guess is something biological. My tongue-in-cheek guess would be something zoological (laser sharks anyone? pigeon pirahna hybrids?)
And in the short-term future, I think synthetic biology will represent an even greater threat than nuclear.
Why? Lethality, ease of manufacture once figured out, mishandling of process or materials, lack of regulation, ethnic/DNA targeting, etc.
Supposedly[2], they are sensitive enough that it's untenable to transport enough lead around to shield it.
1. https://en.wikipedia.org/wiki/National_Nuclear_Security_Admi...
2. I have no inside info.
What changed with nuclear is that you could maintain a credible and scalable strategic deterrent indefinitely at a tiny cost compared to maintaining conventional forces at an equivalent level of deterrence effect.
The only thing nuclear weapons seem to do is ensure their owners are always the aggressors in war and not defenders. Nobody wants to attack a country with nuclear weapons, so it enables them to pick and choose which wars to start.
But seriously these names are pretty much random, sometimes 'cool' sometimes not, just sequential NATO designations like Falcon, Felon, etc.