Hard Light Productions Forums
General FreeSpace => FreeSpace Discussion => Topic started by: Killer Whale on October 16, 2009, 10:23:58 pm
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A Sathanas juggernaut is in orbit below 1000 km above Earth's surface. It's engines get destroyed in a battle and it begins to turn. The juggernaut loses orbit and begins to plummet to the earth's surface. It hits modern day london. What effect would this have on Earth? It takes several terratonnes of dynamite (applied externally) to destroy and is 6km in length. What would happen where it hit? Would life on the planet be extinguished? Or only in britain. Would every human in europe die? A billion people, a million, a thousand, or one? What would be left of the juggernaut? The four spires render, a smoking ship as seen in wheel a fortune freespace style, or would it be instantly vapourised. Discuss
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This. But with London, not Paris.
http://www.youtube.com/watch?v=tGsaOSpNI1Y
EDIT: Of course, a real spaceship in orbit wouldn't just fall down if it lost engines. It would stay in orbit for a very long time, until the orbit decayed.
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In real physics, Earth is no longer a viable habitat for humanity. In FS2 physics, no big deal.
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Well, we could get a(n extremely) ballpark estimate.
Considering how tough the Sathanas is, it should be safe to say that it wouldn't experience any burn-up nor would it explode (either in the air or upon impact).
The speed of impact should be somewhere around orbital speeds, let's say 10 kilometers per second. This is slower than the velocities meteorites can achieve (the meteorite that created the Vredefort Crater could have possibly been traveling at 55 km/s) and remember, the energy carried is related to the square of the velocity.
We'll make an assumption that the Sathanas has a super dense hull, let's say 1 billion tons (note that a solid block of iron the volume of the Sathanas would be more in the order of 100 billion tons).
That would give us a 12 gigaton impact which would certainly be more than simply catastrophic but not really an extinction level event.
Incidentally, Chicxulub is estimated to have been 100 teratons (I plugged in 55km/s [fast meteor] and 500 billion tons [4km cube of iron] and got 180 teratons so my estimation calculation seems to be the right order of magnitude).
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http://www.lpl.arizona.edu/impacteffects/
Play here a little :>
http://www.lpl.arizona.edu/impacteffects/cgi-bin/crater.cgi?dist=2000&distanceUnits=1&diam=5&diameterUnits=2&pdens=&pdens_select=8000&vel=11&velocityUnits=1&theta=30&wdepth=&wdepthUnits=1&tdens=2500
entered some values that would probably represent your scenario, though you normall don't lose your orbit due to engine failure. (I entered 5 km as diameter because the calculator assumes a sphere)
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A sphere of iron 5 kilometers in diameter almost certainly masses more than the spindly Sathanas (of which the primary hull is probably hollow) but at least that calculator seems to agree with my estimate when I adjust accordingly to get a sphere of 1 billion tons.
All that extra information is pretty neat =)
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Nothing much happens to the world. Local destruction is immense, but it wouldn't be anything like an asteroid or comet impact. Relative velocity here is the key. If it would crash on Siberia or Canada, it would cause a lot of windows to break, maybe couple thousand reindeers and bears would snuff it, but that's about it.
Remember, we're talking about an object that is, at the beginning of the scenario, orbiting Earth. That means it has roughly the same velocity as Earth does; at maximum it's velocity relative to surface would be 11.2 km/s at the time of impact which is not exactly fast when you compare it to objects that are orbiting Sun, like asteroids and comets. Very likely the velocity would be significantly smaller, something like seven or eight kilometres per hour would not sound out of place.
Maximum velocity for objects that orbit the Sun is about 72 km/s, for comparision, and typical comet impact velocities are around 50 km/s.
At impact velocities below 15 km/s there is no fireball, the object just plummets to the ground, so no thermal damage. Most damage is caused by seismic vibrations and air blast. If it were to hit an ocean, it would create a tsunami, which would cause more destruction on coastlines, but it wouldn't be the end of world as we know it (except by revealing Shivan existence to the world).
University of Arizona has a handy tool for occasions such as this: Impact effect calculator (http://www.lpl.arizona.edu/impacteffects/)
Estimating the mass of a Sathanas is difficult. I ended up using density of water (1000 kg m^-3) and diameter of three kilometres. Changing the density to iron did not significantly change the outcome. The effects of impact at maximum velocity of 11 km/h were as follows:
Your Inputs:
Distance from Impact: 500.00 km = 310.50 miles
Projectile Diameter: 3000.00 m = 9840.00 ft = 1.86 miles
Projectile Density: 1000 kg/m3
Impact Velocity: 11.20 km/s = 6.96 miles/s
Impact Angle: 45 degrees
Target Density: 2500 kg/m3
Target Type: Sedimentary Rock
Energy:
Energy before atmospheric entry: 8.87 x 1020 Joules = 2.12 x 105 MegaTons TNT
The average interval between impacts of this size somewhere on Earth during the last 4 billion years is 1.4 x 106years
Major Global Changes:
The Earth is not strongly disturbed by the impact and loses negligible mass.
The impact does not make a noticeable change in the Earth's rotation period or the tilt of its axis.
The impact does not shift the Earth's orbit noticeably.
Crater Dimensions:
What does this mean?
Transient Crater Diameter: 14.3 km = 8.91 miles
Transient Crater Depth: 5.07 km = 3.15 miles
Final Crater Diameter: 20.4 km = 12.7 miles
Final Crater Depth: 0.733 km = 0.456 miles
The crater formed is a complex crater.
At this impact velocity ( < 12 km/s), little shock melting of the target occurs.
Thermal Radiation:
What does this mean?
At this impact velocity ( < 15 km/s), little vaporization occurs; no fireball is created, therefore, there is no thermal radiation damage.
Seismic Effects:
What does this mean?
The major seismic shaking will arrive at approximately 100 seconds.
Richter Scale Magnitude: 8.2
Mercalli Scale Intensity at a distance of 500 km:
IV. Felt indoors by many, outdoors by few during the day. At night, some awakened. Dishes, windows, doors disturbed; walls make cracking sound. Sensation like heavy truck striking building. Standing motor cars rocked noticeably.
V. Felt by nearly everyone; many awakened. Some dishes, windows broken. Unstable objects overturned. Pendulum clocks may stop.
Ejecta:
What does this mean?
The ejecta will arrive approximately 334 seconds after the impact.
At your position the ejecta arrives in scattered fragments
Average Ejecta Thickness: 3.03 mm = 0.119 inches
Mean Fragment Diameter: 1.85 mm = 0.0728 inches
Air Blast:
What does this mean?
The air blast will arrive at approximately 1520 seconds.
Peak Overpressure: 11300 Pa = 0.113 bars = 1.6 psi
Max wind velocity: 25.4 m/s = 56.9 mph
Sound Intensity: 81 dB (Loud as heavy traffic)
Damage Description:
Glass windows will shatter.
By comparision, here are results using iron as estimated density:
Your Inputs:
Distance from Impact: 500.00 km = 310.50 miles
Projectile Diameter: 3000.00 m = 9840.00 ft = 1.86 miles
Projectile Density: 8000 kg/m3
Impact Velocity: 11.20 km/s = 6.96 miles/s
Impact Angle: 45 degrees
Target Density: 2500 kg/m3
Target Type: Sedimentary Rock
Energy:
Energy before atmospheric entry: 7.09 x 1021 Joules = 1.69 x 106 MegaTons TNT
The average interval between impacts of this size somewhere on Earth during the last 4 billion years is 6.9 x 106years
Major Global Changes:
The Earth is not strongly disturbed by the impact and loses negligible mass.
The impact does not make a noticeable change in the Earth's rotation period or the tilt of its axis.
The impact does not shift the Earth's orbit noticeably.
Crater Dimensions:
What does this mean?
Transient Crater Diameter: 28.8 km = 17.9 miles
Transient Crater Depth: 10.2 km = 6.32 miles
Final Crater Diameter: 44.8 km = 27.8 miles
Final Crater Depth: 0.929 km = 0.577 miles
The crater formed is a complex crater.
At this impact velocity ( < 12 km/s), little shock melting of the target occurs.
Thermal Radiation:
What does this mean?
At this impact velocity ( < 15 km/s), little vaporization occurs; no fireball is created, therefore, there is no thermal radiation damage.
Seismic Effects:
What does this mean?
The major seismic shaking will arrive at approximately 100 seconds.
Richter Scale Magnitude: 8.8
Mercalli Scale Intensity at a distance of 500 km:
VI. Felt by all, many frightened. Some heavy furniture moved; a few instances of fallen plaster. Damage slight.
VII. Damage negligible in buildings of good design and construction; slight to moderate in well-built ordinary structures; considerable damage in poorly built or badly designed structures; some chimneys broken.
Ejecta:
What does this mean?
The ejecta will arrive approximately 334 seconds after the impact.
Average Ejecta Thickness: 4.89 cm = 1.92 inches
Mean Fragment Diameter: 4.15 mm = 0.163 inches
Air Blast:
What does this mean?
The air blast will arrive at approximately 1520 seconds.
Peak Overpressure: 37000 Pa = 0.37 bars = 5.26 psi
Max wind velocity: 76 m/s = 170 mph
Sound Intensity: 91 dB (May cause ear pain)
Damage Description:
Wood frame buildings will almost completely collapse.
Glass windows will shatter.
Up to 90 percent of trees blown down; remainder stripped of branches and leaves.
In pretty much all cases, damage is limited to radius of a thousand kilometres or so. Even in the case of iron spaceship, which is somewhat implausible but who knows what Shivans build their space ships of...
By the way here's a more interesting question; how much damage did Coruscant suffer when more than half of the Invisible Hand didn't crash on the implausibly well placed runway?
No one even mentions it since it separates from the forward section of the ship. It must've crushed several thousands of beings to death, yet no one even seems to spare a thought to what sort of destruction it would cause. :rolleyes:
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Probably landed on another runway. That's a good site. So it would cause quite a lot of point damage but at several hundred kilometres it'll just make a big boom. Thanks. Oh, and how far do shock-waves travel?
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Well, there is no finite answer, like the answer "how far away does gravity still affect mass"
I think more like your question is "How far until the shockwave is no longer noticable", and the answer is: Won't happen on earth if a Sathanas crashes. Use the calculator and enter as distance 20000km to see how loud the impact would be on the other side of the earth.
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It hits modern day london.
What did i ever do to you? :(
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Yeah what the hell is with that?
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Think of it this way: the majority of scientists believe the asteroid that wiped out the dinosaurs was about 11 km in length, and a little more than half that in width. A Sathanas, big though it is, is not nearly as large as that, and it is not a solid object in the idea that there must be large open spaces within. I don't think the impact would be terribly catastrophic, especially since quite a bit of the ship itself would burn up in reentry. Work from there....
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it's also moving slower.
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The end scene from Alien Resurrection springs to mind...
But not on London :p
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It hits modern day london.
What did i ever do to you? :(
Well destroying New York is something of a cliche at this point. Besides, building low to the ground with few instantly recognizable monuments can only protect you from Hollywood aliens, not real fake aliens :D
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But you could have crashed it in newcastle or brazil or countless other cities... I wouldn't mind only all my stuff's in London :sigh:
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A Sathanas juggernaut is in orbit below 1000 km above Earth's surface. It's engines get destroyed in a battle and it begins to turn. The juggernaut loses orbit and begins to plummet to the earth's surface. It hits modern day london. What effect would this have on Earth? It takes several terratonnes of dynamite (applied externally) to destroy and is 6km in length. What would happen where it hit? Would life on the planet be extinguished? Or only in britain. Would every human in europe die? A billion people, a million, a thousand, or one? What would be left of the juggernaut? The four spires render, a smoking ship as seen in wheel a fortune freespace style, or would it be instantly vapourised. Discuss
It would remain largely intact and would be featured in the FS3 opening cutscene.
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By the way here's a more interesting question; how much damage did Coruscant suffer when more than half of the Invisible Hand didn't crash on the implausibly well placed runway?
No one even mentions it since it separates from the forward section of the ship. It must've crushed several thousands of beings to death, yet no one even seems to spare a thought to what sort of destruction it would cause. :rolleyes:
What a weird thing to complain about. Dude, there were several thousand other ships of comparable mass in orbit and shooting at each other. Coruscant probably got horrifically damaged by hundreds of wrecked destroyers.
I doubt that Coruscant really noticed the half of the Invisible Hand that fell off, in the grand scale of things.
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But you could have crashed it in newcastle or brazil or countless other cities... I wouldn't mind only all my stuff's in London :sigh:
What did I ever do to you?!
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Beat us in numerous world cups :p
It would remain largely intact and would be featured in the FS3 opening cutscene.
This one?
(http://staff.hard-light.net/setekh/the4spires.jpg)
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i'm thinking although the impact itself might not wipe out all life on earth, i'm pretty certain that the dust that is sent into the atmosphere might definitly affect either weather patterns, or sunlight and destroy certain ecosystems. At its worst, block out the sun for a very long time, plants die, we die. At its best, dust gets sent into atmostphere, gets colder, many species die, humanity survives due to technological advancements, reduced human population.
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Nah, we've had much more catastrophic volcanic ejecta than you'd get from a sath tromping London. Bad, yes, but mass extinction catastrophic? No.
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It hits modern day london.
What did i ever do to you? :(
Well destroying New York is something of a cliche at this point...
Exactly. I just thought of the first prominent city that came to my head. The first was Perth (where I live), but I didn't think it was prominant enough. In fact, I'm not sure how many people know it exists. So I thought of another. It was New York. But i don't know much about America and it's way too cliched. The next was London.
But you could have crashed it in newcastle or brazil or countless other cities... I wouldn't mind only all my stuff's in London :sigh:
I don't believe brazil's a city.
By the way here's a more interesting question; how much damage did Coruscant suffer when more than half of the Invisible Hand didn't crash on the implausibly well placed runway?
No one even mentions it since it separates from the forward section of the ship. It must've crushed several thousands of beings to death, yet no one even seems to spare a thought to what sort of destruction it would cause. :rolleyes:
What a weird thing to complain about. Dude, there were several thousand other ships of comparable mass in orbit and shooting at each other. Coruscant probably got horrifically damaged by hundreds of wrecked destroyers...
Not to mention they actually kidnapped the senator with an army on the planet. How many people did they kill to get him before the battle moved into space?
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Beat us in numerous world cups :p
It would remain largely intact and would be featured in the FS3 opening cutscene.
This one?
(http://staff.hard-light.net/setekh/the4spires.jpg)
HO-LEE-****. Where did THAT pic come from? If it's a mod or campaign, I have to have it. Would love any info that goes with that pic....
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It's a fan made render. AFAIK it's just a picture. No campaign or mod is related to it. There are hundreds of pictures like this, none seem to be made into campaigns. Go here (http://staff.hard-light.net/setekh/) to find them
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It would remain largely intact and would be featured in the FS3 opening cutscene.
This one?
*snip*
Or maybe this one?
(http://www.deviantart.com/download/100409488/Crashed_Shivan_Juggernaut_by_Councilor.jpg)
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I ended up using density of water (1000 kg m^-3) and diameter of three kilometres.
Given how tough the newer Shivan ships seem to be it is possible they are made out of more dense materials than that.
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Nah, we've had much more catastrophic volcanic ejecta than you'd get from a sath tromping London. Bad, yes, but mass extinction catastrophic? No.
All of London? Leveled? I say, that would be catastrophic.
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No mass extinction catastrophic though - wouldn't even kill off all the brits - we've got thousands of you down here alone :p
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And when the preperations are complete, we will send our signals and RISE to begin the foundations of the new Empire :lol:
/me hums Rule Britannia as he rocks slowly, kissing the queen on the back of a tenner.
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Would other countries be effected?
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Would other countries be effected?
with a shivan juggernaut in orbit?... I would dare to say yes.
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As to the crash, also yes. It would probably spew an amount of debris into the air (if not comparable to) at least within a couple orders of magnitude of Krakatoa, back in the 1800s. The year it erupted was called the year with no summer, because of all the dust and debris in the air that blocked the sun's rays.
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Personally i say somthing like this:
http://www.youtube.com/watch?v=mL5kOHsgWz8
But i want to know what Orca has against London...If he was from London I would understand, but he isnt even from England So Id like to know whhat his problem is...
EDIT
Nevermind. I just checked his profile. He from Australia, so no wonder he's got beef with us brits :lol:
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All of London? Leveled? I say, that would be catastrophic.
Would it? :drevil:
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Beat us in numerous world cups :p
It would remain largely intact and would be featured in the FS3 opening cutscene.
This one?
(http://staff.hard-light.net/setekh/the4spires.jpg)
Well no I wasn't referring to any specific piece of fan art. Simply saying that if the Hades is going to survive impact and be roughly intact, then surely the Sathanas would be also. Hell the HErcules Mk1 can survive impact largely intact. The FS ships are all pretty fakking durable quite obviously.
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http://www.youtube.com/watch?v=EaJG4Tq88Ek
Interesting despite the "asteroid" being far too large for this conversation. I would have thought more would've happened though.
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There's also the 2/3's chance it'll just boringly land in water, and just cause some lame tsunamis.
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There's also the 2/3's chance it'll just boringly land in water, and just cause some lame tsunamis.
Interstellar collisions do not work that way! Goodnight!
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It's a fan made render. AFAIK it's just a picture. No campaign or mod is related to it. There are hundreds of pictures like this, none seem to be made into campaigns. Go here (http://staff.hard-light.net/setekh/) to find them
A pity we lost Setekh to the abyss of the real world.
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http://www.youtube.com/watch?v=lSygPGLYE-Y
That is all.
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http://www.youtube.com/watch?v=lSygPGLYE-Y
That is all.
No...
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http://www.youtube.com/watch?v=lSygPGLYE-Y
That is all.
No...
Dude... what the?
Is that episode called Boobytrap?!
I can imagine some cooler things under the term "boobytrap" ;7
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Meh, its much more boring than all that. Orbital speeds at 1000km up aren't that fast (I'd say more like 5km/s impact speed), and the sathanas is going to be more like a 3km sphere. Half of it is long arms that you could fold back to stuff it in a box. Also, it is going to have internal space and lots of it. I figure it (like most all ships space and otherwise) would float if it landed in the ocean, so I'd use a density around 1000kg/m^3. Also if its coming down from orbit, it is going to hit at a very glancing angle most likely, so that gives the following impact:
Your Inputs:
Distance from Impact: 150.00 km = 93.15 miles
Projectile Diameter: 3000.00 m = 9840.00 ft = 1.86 miles
Projectile Density: 1000 kg/m3
Impact Velocity: 5.00 km/s = 3.10 miles/s
Impact Angle: 20 degrees
Target Density: 2500 kg/m3
Target Type: Sedimentary Rock
Energy:
Energy before atmospheric entry: 1.77 x 1020 Joules = 4.22 x 104 MegaTons TNT
The average interval between impacts of this size somewhere on Earth during the last 4 billion years is 4.0 x 105years
Major Global Changes:
The Earth is not strongly disturbed by the impact and loses negligible mass.
The impact does not make a noticeable change in the Earth's rotation period or the tilt of its axis.
The impact does not shift the Earth's orbit noticeably.
Crater Dimensions:
What does this mean?
Transient Crater Diameter: 7.87 km = 4.89 miles
Transient Crater Depth: 2.78 km = 1.73 miles
Final Crater Diameter: 10.3 km = 6.43 miles
Final Crater Depth: 0.598 km = 0.371 miles
The crater formed is a complex crater.
At this impact velocity ( < 12 km/s), little shock melting of the target occurs.
Thermal Radiation:
What does this mean?
At this impact velocity ( < 15 km/s), little vaporization occurs; no fireball is created, therefore, there is no thermal radiation damage.
Seismic Effects:
What does this mean?
The major seismic shaking will arrive at approximately 30 seconds.
Richter Scale Magnitude: 7.7
Mercalli Scale Intensity at a distance of 150 km:
VI. Felt by all, many frightened. Some heavy furniture moved; a few instances of fallen plaster. Damage slight.
VII. Damage negligible in buildings of good design and construction; slight to moderate in well-built ordinary structures; considerable damage in poorly built or badly designed structures; some chimneys broken.
Ejecta:
What does this mean?
The ejecta will arrive approximately 177 seconds after the impact.
Average Ejecta Thickness: 1.01 cm = 0.399 inches
Mean Fragment Diameter: 2.23 cm = 0.879 inches
Air Blast:
What does this mean?
The air blast will arrive at approximately 455 seconds.
Peak Overpressure: 34600 Pa = 0.346 bars = 4.92 psi
Max wind velocity: 71.7 m/s = 160 mph
Sound Intensity: 91 dB (May cause ear pain)
Damage Description:
Wood frame buildings will almost completely collapse.
Glass windows will shatter.
Up to 90 percent of trees blown down; remainder stripped of branches and leaves.
At 150 km, you get a magnitude 7.7 earthquake, and a nearly fatal airblast. Thats about the destructive limit, so you wipe out most of England, but probably not too much more.
I assume the sathanas is made out of a very light and hard superalloy so it is probably sitting half buried in the crater.
On that note, the impact simulator assumes that the projectile uses energy from the impact to destroy itself. If the sathanas survives, it may end up buried much deeper under the crater, and may supress a lot of air blast, making the crash even less destructive.
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Meh, its much more boring than all that. Orbital speeds at 1000km up aren't that fast (I'd say more like 5km/s impact speed)
Remember that you need to consider the kinetic energy from the thousand (well, about 900 km or so till atmosphere starts to decelerate it measurably) kilometre descent as well.
The only way an object from high earth orbit would suddenly fall to earth is if it's velocity suddenly decreased enough to bring the perigee inside the planet's surface sphere. For sake of simplicity, let's say that the object is at roughly 3600 kilometres altitude spherical orbit (10000 km orbital radius). At this situation, orbital velocity is slightly less than 6000 m/s (5900 m/s to be exact).
Suddenly, the ship's thrusters grossly malfunction due to battle damage or Carl's lunch dripping blood over control panels and causing a short, whatever. The thrusters fire up in retrograde direction, which causes the orbital velocity to decrease. The required velocity change to bring the perigee within the planet's surface(orbit intersects planet ie. collision occurs) is about 700 m/s from this particular orbit; when orbital velocity at 10000 km apogee is less than approximately 5200 m/s, the orbit's perigee sinks below the planet's surface. This means a very shallow impact angle, however; for greater impact angle the delta v needs to be larger, and correspondingly the impact velocity will be slightly less.
(http://img39.imageshack.us/img39/4499/orbitfall1.png)
However, from this point the ship's velocity increases as it's falling towards the planet. Crossing the semi-minor axis point, the orbital velocity is already at about 7000 m/s and increasing.
(http://img10.imageshack.us/img10/5219/orbitfall2.png)
At the beginning of atmospheric entry, velocity is about 8200 m/s which is scarily close to my initial estimation of 8 km/s which I presented here (http://www.hard-light.net/forums/index.php?topic=66160.msg1305130#msg1305130) :nervous:. I flew a delta glider in Orbiter to test the numbers (it was faster than calculating and more fun) and a Sathanas would have the same trajectory up until the point of atmospheric entry, after which it wouldn't be significantly slowed down by atmosphere like my puny little glider - it would hit the ground at around 8 km/h with this kind of start-up orbital situation.
(http://img40.imageshack.us/img40/8337/orbitfall3.png)
...and the sathanas is going to be more like a 3km sphere. Half of it is long arms that you could fold back to stuff it in a box. Also, it is going to have internal space and lots of it. I figure it (like most all ships space and otherwise) would float if it landed in the ocean, so I'd use a density around 1000kg/m^3. Also if its coming down from orbit, it is going to hit at a very glancing angle most likely, so that gives the following impact:
Sounds pretty much the same as my rationales for my values earlier. :)
Of course, nothing forces the Sathanas to settle on an orbit to begin with - it could be on hyperbolic trajectory around Sun and hit the Earth at any given speed within reasonable limits. Something like 100 km/s wouldn't sound too impossible for such situation if you want to maximize the destruction...
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Now calculate the impact force of a Sathanas going 25 m/s.
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Much less? That's like 0.025 km/s...or 90 km/h...
About the speed of a truck on a highway.
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Now calculate the impact force of a Sathanas going 25 m/s.
Impact force depends on how fast it stops.
F = m dv/dt
m = mass
dv = change of velocity in certain time dt.
Kinetic energy is ½m*v2 and impulse of the impact is m*v, but the impact force depends on what it hits. The faster it stops, the faster the kinetic energy is converted into thermal enrgy, mechanical work (which is spent on transformations of both impact soil and the ship itself, as well as seismic waves) and small amount of gravitational waves. There are differences whether it hits earth, sedimentary or crystalline stone, or water, how deep and what the ocean bottom is made of... Basically, the softer the impact, the less "sharp" the seismic waves, meaning their peak amplitude is somewhat reduced. Total energy released in the impact is same, but it would manifest in different forms.