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Author Topic: series of questions of asteroids for my fictional drama story.  (Read 429 times)

Offline dtheman25

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I'm thinking up a drama story involving asteroid on a collision course with Earth. Telekinesis is involved in the climax (this story is not a usual route of superhero story, it's an entirely different story). I’m not an expert on physics or astronomy, though I looked at some video documentaries and quick researches so I have good ideas about asteroids. I'm a busy man, but I would like to save the story for possible future writing, so I wouldn't forget the whole story. The story is not about asteroid, which only appears in the final day/climax (so I’m not very concerned with it), but I would like the climax to be atleast realistic (I can bend science a little for the sake of story and entertainment), though telekinesis is involved. Once I know the answers to these questions below, I can work around the story’s third act and ending as well as research better into asteroids. I don't mind ballpark answers. NOTE: I would not be giving myself credits for science research (I really don't care for it, anyway). I would be more than happy to give credits to any people who  help me with questions about asteroids/meteors/comets.

Quicknote about my story: the size of main asteroid may be Texas/Germany (although it may be smaller), and its impact location is Switzerland (I may change the location). That main rock is very dense, maybe iron-dense. The angle of impact is close to 90 degree. I'm not sure what the speed would be, but assuming it is the minimum speed (to ensure long climax, unlike most movies/stories). There are three far smaller rocks, which would be mentioned later on. The climax takes place at a huge open space (park) outside of London at sunset. Assuming the sky is cloudless and filled with basketball-size rocks hitting all over Europe.

You don't have to answer them all (one or more would be good). Sorry for lot of questions, I have to be thorough with the climax, and I may ‘bend’ some science as well.

1. If the main rock is the size of Texas/Germany and heading toward to Switzerland from the sky, can people in a huge open space outside London see it? How far in the sky would people in Europe (more importantly, in London) be able to see the main asteroid? How much further the main asteroid’s impact location can the people from London be able to see? (e.g. If the main rock’s impact location is north of Africa, can people in London still see it in the sky?) What would be the countdown left of impact by the time people in London first see the main rock? 8 minutes?

2. Assuming at minimum speed, by countdown, when would the main asteroid burst into flame (due to build up friction in atmosphere; not like Tunguska event)? 4 minutes before? How far from land to atmosphere/sky would that usually be? Where would that ‘bursting into flame’ usually occur in the atmosphere?

3. There are three far smaller rocks, which one’s impact location in west of Russia and the other in south of Atlantic Ocean (I’m not sure where the third would hit yet). However, they may change due to uncertainty of climax’s scientific accurate. Anyhoo, I have similar questions as previous ones.

3a. What would be the size of those smaller rocks to wipe out only west of Russia as well as to create a mega-tsunami to wipe out only South America and Africa? (I don’t hate them; just need to raise some tension). I’m hoping the damage would be concentrated (i.e. the damage only affect its surrounding area of impact, not global).

3b. From the established size of those smaller rocks, is it possible for the people outside London to see these smaller rocks falling from the sky all the way to west of Russia and south of Atlantic Ocean? How big do they have to be? These three rocks are in the same direction as the main asteroid to Earth, same with the angle of impact to be close to 90 degree (or less since the impacts are in different area). This question is important for the climax, and if it’s scientifically impossible, would it be acceptable to ‘bend’ these science/physics? Would ‘bending’ these science require too much suspension of disbelief (I hope not)?

Questions involving telekinesis (providing that the questions above are acceptable)...

4. Henry (let’s call him; who have telekinesis), from outside of London, would move the main asteroid to above England and stop the main asteroid head-on w/ his telekinesis power. With the main asteroid ON FIRE in the air directly on top of England, what is the acceptable distance between the flaming rock and the land that the flaming rock would not affect the environment down below?

5. When the main asteroid is pushed up back into space, what happened to the fire? Would it disappear due to no oxygen in space? What would the main rock look like in space like since it never hit Earth? I remembered watching a documentary that before the asteroids hit, the rock’s surface would ‘melt’.

6. Concerning with the three smaller rocks, Henry diverted some of these rocks (i.e. changed their courses), making them to miss Earth (the reason why question 3b is important). How far off from land would these three small rocks have to be so Henry (providing that the he can see all these three small rocks from London) can divert them before the gravity from Earth have any effect on these smaller rocks?


 

Offline Atomic-S

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This sounds like a very complex piece of physics.  In rough terms regarding some of the more basic questions:  The escape velocity from the Earth's surface is, I believe, around 26,000 miles per hour.  That would also be the speed at which an object, moving relatively slowly with respect to Earth, would hit the Earth if the object were drawn in be the Earth's gravity. An asteroid would likely have additional kinetic energy due to its different orbit, but the orbit is at least in the same general part of the Solar System.  So that might be giving you an idea as to what sort of speed you need to be thinking about. Figuring out the visibilities of such objects is a matter of geometry:  How far away does something the size of Germany need to be to be as visible to a Londoner as is the Moon?  It is a matter of proportional triangles.  Once you figure out that, then using the object's speed from that point to the Earth gives you the travel time between those two points. Keep in mind that the object will be traveling its fastest near the Earth.  You might look up the history of the Apollo moon flights to get an idea of how the trajectory of those spacecraft went, which would, in terms of timing, be somewhat similar; although an asteroid would likely travel somewhat faster. 

The substantive atmosphere of the Earth ends around 20 miles above the surface, roughly speaking. It does extend higher, of course, but very thinly.  Using 20 miles as a rough figure, the time during with the asteroid will be traversing the atmosphere at 26,000 MPH is 2.77 seconds.  This scene will be over quickly. 

The width of Germany is about 470 miles. The asteroid of that size, on first encountering the atmosphere, will be simultaneously hitting it over maybe an effectively 60 mile wide circle, which will widen quickly as it approaches. The air will be squeezed between this and the Earth's surface in a thickness of 20 miles, rapidly decreasing. It will all be over in 2.77 seconds.  That will be extreme compression and a terrific blast. I am not sure the earth would survive this.
 

Offline Atomic-S

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Running through some thermodynamics, I apply the fact that the density of air at the surface is about 0.1% that of water, so that the process of gaseous compression would apply up to that point, at which point it is effectively no longer a gas. Making some rough estimates, I conclude that by the time the atmosphere has been compressed under the asteroid to that point, the temperature would have reached in the neighborhood of 27,300 K. 
 

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