Anyone with a planetary science background (or interest in the field), please step inside

[Drew Kerman]

I have a Class E asteroid on trajectory to skip through Kerbin's atmosphere at 30km. This is a legit no-kidding honest to goodness actual in-game event generated by the asteroid system (currently being managed by the Custom Asteroids mod). Thanks to the KSPTOT program, I also know its exact trajectory through the atmosphere, modeled with FAR. I'm interested in discussing with anyone who is willing to offer insight how this event would affect Kerbin. Right now I'm thinking the massive shockwave would plow a wide swath of destruction - tearing up surface ground, flattening everything beneath it and setting fire to forests on the edge of the super-heated air column. Any time spent over oceans would likely flash boil a good portion of the surface water. The asteroid, being a huge Class E, won't break up entirely but lots of pieces, some still large, will break off and rain down as well along a path longer than that of the main asteroid's travel through the atmosphere, maybe some going into highly eccentric orbits to rain down days later. Long-term effects will include massive rain storms from all the extra moisture in the air leading to large scale flooding, and smoke from all the wildfires spreading around the globe, potentially kicking off a small-scale cooling trend. The swath of destruction should even be visible from space, although how I'm going to do that in the game I've not yet figured out - might just have to do some post image editing.

Anyways, additional thoughts and comments are welcome. Please PM or include responses in spoiler tags. I like to think some people would actually care not to know this until it happens That would be on 3/27. Here is the ground plot:

Edited February 8, 2015 by Gaiiden

[KerbMav]

Just reminded me of theses:

http://simulator.down2earth.eu/input.html?lang=English

http://www.purdue.edu/impactearth/

http://www.killerasteroids.org/impact.php

[Ralathon]

It kind of depends on how strong the asteroid is. There are 2 options here:

1 - it skips out of the atmosphere. In this case it might shatter a few windows but not much else. The asteroid takes most of its energy with it back out of the atmosphere.

2 - It disintegrates and causes an airburst. In this case all the kinetic energy of the asteroid is dumped into the atmosphere. For Kerbin this still won't do much because E class asteroids aren't all that big and the orbital speeds aren't that high. If the E class would hit Earth it'd be equivalent to about 180 kilotons of TNT. So it would likely cause a miniature Tunguska Event.

[RatchetinSpace]

I think its unlikely that the asteroid would cause global fires and mass destruction, (For one thing Kerbin has no forests :-P) but it depends on whether you want this to be accurate with real world.

1. Real life Physics: For starters, the asteroid isn't hitting the planet directly, but rather skimming through the higher atmosphere and then falling as a result of lost velocity. This means the asteroid is going to lose a lot of its energy, and its also more likely for it to burn up. The problem is in KSP the asteroids and planets are small compared to real life, and also the asteroids generated are in similar orbits to Kerbin and will also be travelling more slowly. Overall, there's going to be less mass and less speed behind the impact.

2. Made up Physics: Lets ignore the boring stuff and say that this asteroid had enough energy behind it to deal some serious damage. An asteroid impact wouldn't cause many fires, (They would probably be contained to within a 5-30 km radius depending on the size of asteroid) however it would launch a lot of debris into the atmosphere and space as well as create great shock waves that cause tsunamis, earthquakes and volcanic eruptions (assuming Kerbin has all of those). The material released by these events would enter Kerbin's atmosphere and block out the sun, causing mass extinction to lots of living things. Since Kerbin is way smaller than the Earth, this event would be felt all over the planet and would have a devastating impact on all species.

There are lots of other things that could be covered here like different types of asteroids with different composition however this is the best explanation I could give and I am by no means an expert. It'll be interesting to see what other people have to say

[magnemoe]

It kind of depends on how strong the asteroid is. There are 2 options here:

1 - it skips out of the atmosphere. In this case it might shatter a few windows but not much else. The asteroid takes most of its energy with it back out of the atmosphere.

2 - It disintegrates and causes an airburst. In this case all the kinetic energy of the asteroid is dumped into the atmosphere. For Kerbin this still won't do much because E class asteroids aren't all that big and the orbital speeds aren't that high. If the E class would hit Earth it'd be equivalent to about 180 kilotons of TNT. So it would likely cause a miniature Tunguska Event.

I doubt it would have serious impact, the one who exploded over Russia some years ago was larger than E class if I remember correctly.

It don't look like high attitude asteroid explosions is as dangerous as nukes, probably as the explosion takes some seconds. An low attitude explosion would be worse as the fragments would burn up much faster in the dense air. For impact this would be instant.

[Newt]

Class E says nothing about makeup. It could be a rubblepile, and will do nothing apart from cause interesting lights, or it could be a solid lump or iron, which will have much more damage potential.

[lajoswinkler]

Just reminded me of theses:

http://simulator.down2earth.eu/input.html?lang=English

http://www.purdue.edu/impactearth/

http://www.killerasteroids.org/impact.php

I doubt these links would help. After all, asteroids in KSP have very different densities.

[The Jsaur]

I doubt these links would help. After all, asteroids in KSP have very different densities.

It's possible to manually enter densities on the second site. Plugging in the statistics, though, shows that there will be very little actual damage.

[Drew Kerman]

well shucks guys, I've done some more research given that most of you think it won't be that big of an event and looks like it won't - although I will admit that my original ideas were based on Class E rocks being closer to a kilometer or more in size I totally forgot to actually check how big they are in the game I mean, I'm doing my own fiction thing so I could always say they are bigger but then when I actually go visit one at some point I might have a continuity issue, heh. It'll happen mostly over water too so not really much to write about - although it will definitely spur the government to finally help fund a Sentinel-type mission

[Bill Phil]

Maybe have an airburst resulting in a bunch of E class roids scattering around and one could hit a city, in Italy.

[Newt]

Even if it is not as exciting as it could be, this is pretty neat -- I have never heard of an asteroid getting this close to Kerbin before, so I will be excited to see what happens.

[Drew Kerman]

Even if it is not as exciting as it could be, this is pretty neat -- I have never heard of an asteroid getting this close to Kerbin before, so I will be excited to see what happens.

oh yea, no - I'm still excited about the event. It's going to be a galvanizing one for the kerbals regardless

[flamerboy67664]

Hi, owner of the 872nd here. This is not the certainly first time where a Class E (with Custom Asteroids) swooped around Kerbin. Around October, I saw an asteroid with an apkerbion 2 times the distance of Eeloo on an atmospheric skimming trajectory. The periapsis of the object reached 14 kms above the surface. What I did is send a craft with a jetplane attached to it, then when it skims the atmosphere at that high speed, I detach the plane and chased the roid until it skimmed out of the atmosphere. RIP Berndor Kerman. You have died for science.

EDIT:

872nd SOLC will be ready and get the conventional K4A conventional kinetic anti-ballistic missiles ready (holy crap Kraken's Belly is really goddamn close in that path)

when this is cannon to the UK/UKKR storyline.

Cheers, flamerboy67664/SpaceEagle

Edited February 14, 2015 by flamerboy67664

[Newt]

@Flamerboy.

Interesting. Have you screenshots? That sounds like a comet!

[Carl Sagan The S Stallion]

Before I begin my analysis, I would like to say that I am an aspiring physicist and an intern at the emergency management office for a major city in the United States.

Honestly, in real life, as explained before, an asteroid like this would not do much damage at all. It's simply too small to do anything and would probably burn up in the atmosphere.

Now, consider what would happen if it were bigger. MUCH bigger. Like, REALLY big.

Suppose Gilly was on a collision course for Kerbin

Now that might deal some serious damage. Looking at it from the aspiring physicist's point of view, I don't see this asteroid burning up in the atmosphere, but colliding with the ground and having a fairly big impact (pun intended).

If it impacts the mainland, it would cause a fairly large shockwave and knock over some houses and structures. It would probably flatten entire forests for a 230 square km (90 square mi) radius. Beyond that, minor tremors would deal practically no damage whatsoever. Within that radius, you would see damage to infrastructure (bridges, railways, dams, etc) closer to the impact area, as well as loss of life much closer. The majority of life lost would be in the immediate impact area and near the shockwave. Biologically, the shockwave, should it be strong enough, could cause major trauma that decreases in severity with increasing distance from the impact area. However, just like with an earthquake, the majority of injuries would be from building collapse and falling objects.

If it impacts the ocean, it would cause practically no damage in the impact radius, but I couldn't say the same for the fish. The damage it would do, however, is in a tsunami, coming from the impact's tremors. However, unlike a tsunami formed from a earthquake or underwater landslide, this tsunami would be one single wave, rather than three that bunch up, and it would have done less serious damage than a tsunami. Depending upon the distance from the coastline, coastline infrastructure and geography, and time of day, the tsunami would have varying degrees of damage. If it hits full force, it would wipe out coastal residential neighborhoods, old structures, and tall, unsupported structures (specifically buildings with weak foundations or buildings without pylons that are driven into the foundation to prevent lateral movement). Meteorologically, however it would be interesting to see if any storms come from this impact. It would be an interesting proof of concept to see a hurricane come from the impact (the impact evaporates a considerable amount of water in the surrounding area and this forms into a storm, the largest of which, could be a hurricane; it's a hypothesis that one of these was formed during the cretaceous extinction, a massive one, and punched a hole in the ozone layer by throwing enough water up there).

Looking at it from an emergency manager's point of view, the main concern would be in immediate emergency services. In a mainland collision, seeing how power lines and telecommunications would be cut, it would be up to the local populous to take care of immediate threats for the first day or so. Once emergency supplies start flowing, emergency services would have a very limited time to pull people from the rubble of collapsed buildings and establish medical centers to take care of the wounded. The concern with this is the infrastructure; damaged bridges, cut powerlines, and broken gas lines would pose a serious threat to any rescue attempts, even preventing supplies from being ferried to the proper locations. After the first five or so days, most of the search and rescue effort would have been concentrated on body recovery (those poor Kerbals). Meanwhile, the first engineers arrive to help repair critical infrastructure and get more supplies flowing. Food would be scarce without this, since most of the food before the disaster would be gone and without much supplies coming in to supplement, and people would go hungry. Following that, is the recovery to individual property. This is the longest phase, since most individuals would not have the liquid capital to begin repairs on the houses and businesses; I hope they had asteroid insurance.

Should the asteroid impact the ocean, the main concern would be getting the word out before the tsunami hits. When it does, damage described above would be vary. Being that I live in a desert, I can't say much about the emergency response.

However, we are not talking about Gilly. This is a 30m diameter object. It would not do any damage whatsoever.