Threat Of An Asteroid Attack

[SNOW-MAN2006]

so,

well after watching a program on TV last night about the threat of a meteorite attack I thought I’d start a discussion on it

WHAT'S THE RISK??

The asteroid belt (situated between Jupiter and mars) is orbiting Jupiter. Every now and then these collide and are sent hurtling in another direction. They think that the last meteorite wiped out the dinosaur and enabled the human race to evolve and become top dog. if a meteorite big enough (3 km wide) hit say san Francisco it would cause a massive dust storm to rattle over north America in an hour and cause a massive earth quake causing tidal waves etc.

PROOF???

in 1998 a meteorite hit Jupiter. nothing was though to it and people thought that nothing would happen from it but 1 year on and the scars were revealed. if a big enough meteorite hit earth it could plough straight through it and come out the other side as it travels 30 time faster than a fighter jet and could cross northern America in the space of an hour!

PREVENTION???

The only country keeping an eye out on meteorites is America and only put forward 4 million dollars a year into research. How far will that go. You may ask well why don’t we blow it to smithereens with nuclear weapons well we could but if you want to live with cancer then you may because if we blow it up the rocks would disintegrate in the atmosphere but the dust particles would be henceforth radioactive. There is one theory to invent a MASISVE magnifying glass and burn it up but the smoke released would propeller it away. Another method would to build a big tweezer and move it out the way of earth.

CONSEQUENCES???

if a meteorite was to hit the blue plant then for 1) we would be wiped out 2) plant life would die as massive dust storm will block out light for many years 3) a new ice age would be born

feel free to discuss

SNOW-MAN2006

p.s sorry for earlier post never realised so many mistakes in

Edited April 10, 2006 by SNOW-MAN2006

[osmposm]

Look, Snow-man, I try not to get too worked up about people's spelling and grammar on here, as long as it's clear what they're saying.

But a fair bit of what you're trying to say is incomprehensible because of how it's written. What does "..another method would to build a big tweerer and move it out the way of earth" mean? I have absolutely no idea. Or "if a meterorite was to hit the blue plant then for 1) we would be wiprd out..""?

Sorry, the way we write our language may seem like a boring waste of time to you, but the whole point of it is to make what we're saying understandable to other people. How can we have a sensible discussion otherwise? Couldn't you at least use the spell-check on your computer?

End of grumble !!

[Gray-Wolf]

Don't worry, it's the shattered comet due in May you should concern yourself with!!!

[osmposm]

p.s sorry for earlier post never realised so many mistakes in

Thanks for the corrections, Snow-man....though I'm not sure a big tweezer makes any more sense than a big tweerer as a possible means of moving threatening lumps of cosmic debris?!

[Cloudburst]

Don't worry, it's the shattered comet due in May you should concern yourself with!!!

:lol: :lol: . yes 6 million miles is quite close, but its not going to hit us thats for sure.

Edited April 10, 2006 by ¤CloudBurst¤

[Guest Daniel]

so,

well after watching a program on TV last night about the threat of a meteorite attack I thought I’d start a discussion on it

WHAT'S THE RISK??

The asteroid belt (situated between Jupiter and mars) is orbiting Jupiter. Every now and then these collide and are sent hurtling in another direction. They think that the last meteorite wiped out the dinosaur and enabled the human race to evolve and become top dog. if a meteorite big enough (3 km wide) hit say san Francisco it would cause a massive dust storm to rattle over north America in an hour and cause a massive earth quake causing tidal waves etc.

PROOF???

in 1998 a meteorite hit Jupiter. nothing was though to it and people thought that nothing would happen from it but 1 year on and the scars were revealed. if a big enough meteorite hit earth it could plough straight through it and come out the other side as it travels 30 time faster than a fighter jet and could cross northern America in the space of an hour!

PREVENTION???

The only country keeping an eye out on meteorites is America and only put forward 4 million dollars a year into research. How far will that go. You may ask well why don’t we blow it to smithereens with nuclear weapons well we could but if you want to live with cancer then you may because if we blow it up the rocks would disintegrate in the atmosphere but the dust particles would be henceforth radioactive. There is one theory to invent a MASISVE magnifying glass and burn it up but the smoke released would propeller it away. Another method would to build a big tweezer and move it out the way of earth.

CONSEQUENCES???

if a meteorite was to hit the blue plant then for 1) we would be wiped out 2) plant life would die as massive dust storm will block out light for many years 3) a new ice age would be born

feel free to discuss

SNOW-MAN2006

p.s sorry for earlier post never realised so many mistakes in

If an astroid was ever to come our way Im afraid nuclear weapons are the only thing we have to deal with it. Anyway shuch an event so is rare we be very unlucky if it did ever happen. but as I said we do have the neclear option and if that saves us from being whipped out than that what we have to use and we may just have to put up with any side effects. but as it so rare it something Im not going to worry about. I far more worried about the state of the gulf stream. Last year we had many reports of it Weaking and the much colder weather that will bring. a report on the Gulf stream slowing down says we could lose 5 degrees or more in our Averge temps over the U.K and Europe. if does occure it will have massive effect on our climate and weather. if that was to happen our average winter climate would be colder than the great freeze of 1683/84 when there was blinding snow storms and rivers froze for more than 12 weeks and trees died of frost plus the sea froze as well. Our Springs would be so cold that snow would lye on the ground until mid April and Periods of snow and frost would occure right up to June. It would be a massive change and this could cause a dangerous cycle of long term cooling that would lead to the next ice age. So far this year we have been cold. Though there been no great freeze temperures have been greatly suppressed so far this spring. The reason for this is that the warm winds have been much weaker and more highs forming in the wrong postions that to the north and west. this well be the first signs that the changes in the Gulf Stream are having a big effect on us and there a chance that this cold could last through out the year.

[osmposm]

......it so rare it something Im not going to worry about. I far more worried about the state of the gulf stream. Last year we had many reports of it Weaking and the much colder weather that will bring.

Daniel, Daniel, this is a thread about the threat (or not) to Earth of impacts from cosmic bodies. Almost exactly 75% of your post is about the Gulf Stream.

You've been asked in a very friendly way by the mods not to start any more identical threads about NAD shutdown just for the moment. That doesn't mean the answer is to insert your obsession into any other threads that take your fancy...this thread isn't even about climate, for goodness' sake !!!!!!

[BARRY]

the last big impact ocurred in tanguska in siberia in 1908 when a 200ft meteorite exsploded

five miles above the earth releasing between 20 & 30 megatonnes of energy,killing all living creatures & flattend every tree within a 20 mile radius, the area being so remote that no one

lives there this is a once in a millenium event & with modern radio telescopes, rader, and satalite detection i think we are in better shape to detect big rocks from space.new theory is that it may heve been an alian space craft because of the amount of radation found there that normaly comes from an atomic source

also around about 100,000 tons of cosmic dust enters earth's atmospere every year

BARRY

Edited April 10, 2006 by BARRY

[drgl]

Daniel, Daniel, this is a thread about the threat (or not) to Earth of impacts from cosmic bodies. Almost exactly 75% of your post is about the Gulf Stream.

You've been asked in a very friendly way by the mods not to start any more identical threads about NAD shutdown just for the moment. That doesn't mean the answer is to insert your obsession into any other threads that take your fancy...this thread isn't even about climate, for goodness' sake !!!!!!

lol-i've got to agree,it WAS interesting and MAY still turn out to be interesting but just now we've had a fair few too many posts rambling on about it! Lets wait another 12 months and see what's happening then? I'm not against you-i fully believe we will return to colder conditions in the next few years but lets leave if for a while...........................

[BrickFielder]

Check out what the torino scale is Here

Close Approaches coming up

Here can be seen the potential threat from all known comets and asteroids.Perhaps a low chance of one hitting in 2102.

Risk of collision

[SNOW-MAN2006]

lol-i've got to agree,it WAS interesting and MAY still turn out to be interesting but just now we've had a fair few too many posts rambling on about it! Lets wait another 12 months and see what's happening then? I'm not against you-i fully believe we will return to colder conditions in the next few years but lets leave if for a while...........................

well put forward. this is a thread about the threat of an astroid attack that may hit the earth and what would happen if it did. please dont turn it into another one of your gulfstream weakening discussion.

on the other hand thank-you for that link brickfielder. very informative and nice to know that nothing is set to hit us in my life span

also around about 100,000 tons of cosmic dust enters earth's atmospere every year

BARRY

that may be so but if all of that 100,000 tons came in one big ball surely you would notcie something

Edited April 11, 2006 by SNOW-MAN2006

[Scribbler]

A potentially fascinating thread, Snow-man.

We know so little about such wandering lumps of rock that there is always a chance of one hitting us. People such as NASA do search (as you point out) for such hazards – but they are constantly adding new asteroids to their list of Near Earth Objects.

http://www.impact.arc.nasa.gov - Asteroid and Comet Impact Hazards.

Their searches are certainly not all-encompassing either.

Asteroids are hard to see, and detecting those as small as a hundred metres in diameter (the ones capable of levelling a city) may take time, even with a more sophisticated search effort.

Nor would such a search warn us of the rarer but potentially more lethal long-period comets: an early-warning system capable of detecting those in time might require that sensors be deployed beyond the orbit of Jupiter.

It has been said that a long-period cometary sun-grazing asteroid wouldn’t been seen until it was merely a few weeks away.

Not a bad (fiction) book on the subject is Moonfall by Jack McDevitt - the story of such an asteroid (a large one) impacting on and shattering the moon.

For a bit of fun, check out:

http://www.lpl.arizona.edu/impacteffects/

Drop your own asteroid on the earth!

[osmposm]

For a bit of fun, check out:

http://www.lpl.arizona.edu/impacteffects/

Drop your own asteroid on the earth!

Whoaaaa - that link's very freaky, Scribbler: I've just been chucking a variety of large objects at Great Britain in various places between Windsor and Edinburgh with fascinating results. A dense-ish 200 metre asteroid at average speed on Edinburgh rearranged things a bit up there; but I'm glad to say all we got here was a bit of mainly light dust and a distant rumble of sound......or maybe that was just Shuggee complaining !

[kold weather]

Ah, yes I saw that program last night, can't think what channel it was on mind you!

I certainly think its a danger to the earth, and as the program said just 50% of the large NEA have been found, which means there are probably still hundreds out in space possibly with our name on.

Nuclear weapons are a big no-no when it comes to certain types of asteriods.

You either shatter them into large pieces and the net result is the same, or they re-form back into the same large asteroid it was before. If you were to get a big enough bomb I suppose you could take out the 1 rock asteroids, but the rubble pile, its a big no-no!

(ps, yes this is a ASTERIOD thread...not a gulfstream thread!)

[shuggee]

I didn't know asteroids could attack us.

[Methuselah]

Whoops Apocalypse!

Impact Effects

Robert Marcus, H. Jay Melosh, and Gareth Collins

Please note: the results below are estimates based on current (limited) understanding of the impact process and come with large uncertainties; they should be used with caution, particularly in the case of peculiar input parameters. All values are given to three significant figures but this does not reflect the precision of the estimate. For more information about the uncertainty associated with our calculations and a full discussion of this program, please refer to this article

Your Inputs:

Distance from Impact: 161.00 km = 99.98 miles

Projectile Diameter: 500.00 m = 1640.00 ft = 0.31 miles

Projectile Density: 8000 kg/m3

Impact Velocity: 24000.00 km/s = 14904.00 miles/s (Your chosen velocity is higher than the maximum for an object orbiting the sun)

Impact Angle: 12 degrees

Target Density: 1000 kg/m3

Target Type: Liquid Water of depth 195.00 meters, over typical rock.

Energy:

Energy before atmospheric entry: 1.51 x 1026 Joules = 3.60 x 1010 MegaTons TNT

The average interval between impacts of this size is longer than the Earth's age.

Such impacts could only occur during the accumulation of the Earth, between 4.5 and 4 billion years ago.

Atmospheric Entry:

The projectile begins to breakup at an altitude of 130000 meters = 427000 ft

The projectile reaches the ground in a broken condition. The mass of projectile strikes the surface at velocity 22700 km/s = 14100 miles/s

The impact energy is 1.35 x 1026 Joules = 3.21 x 1010MegaTons.

The broken projectile fragments strike the ground in an ellipse of dimension 6.33 km by 1.32 km

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?

The crater opened in the water has a diameter of 215 km = 133 miles

For the crater formed in the seafloor:

Crater shape is normal in spite of atmospheric crushing; fragments are not significantly dispersed.

Transient Crater Diameter: 115 km = 71.2 miles

Transient Crater Depth: 40.5 km = 25.2 miles

Final Crater Diameter: 214 km = 133 miles

Final Crater Depth: 1.49 km = 0.924 miles

The crater formed is a complex crater.

The volume of the target melted or vaporized is 134000 km3 = 32200 miles3

Roughly half the melt remains in the crater , where its average thickness is 13 km = 8.08 miles

Thermal Radiation:

What does this mean?

Time for maximum radiation: 0.0452 seconds after impact

Your position is inside the fireball.

The fireball appears 1440 times larger than the sun

Thermal Exposure: 2.47 x 1012 Joules/m2

Duration of Irradiation: 13300 seconds

Radiant flux (relative to the sun): 186000

Effects of Thermal Radiation:

Clothing ignites

Much of the body suffers third degree burns

Newspaper ignites

Plywood flames

Deciduous trees ignite

Grass ignites

Seismic Effects:

What does this mean?

The major seismic shaking will arrive at approximately 32.2 seconds.

Richter Scale Magnitude: 11.5 (This is greater than any earthquake in recorded history)

Mercalli Scale Intensity at a distance of 161 km:

X. Most masonry and frame structures destroyed with their foundations. Some well-built wooden structures and bridges destroyed. Serious damage to dams, dikes, embankments. Large landslides. Water thrown on banks of canals, rivers, lakes, etc. Sand and mud shifted horizontally on beaches and flat land. Rails bent slightly.

XI. As X. Rails bent greatly. Underground pipelines completely out of service.

XII. As X. Damage nearly total. Large rock masses displaced. Lines of sight and level distorted. Objects thrown into the air.

Ejecta:

What does this mean?

The ejecta will arrive approximately 184 seconds after the impact.

Your position is in the region which collapses into the final crater.

Your position is beneath the continuous ejecta deposit.

Average Ejecta Thickness: 370 m = 1210 ft

Air Blast:

What does this mean?

The air blast will arrive at approximately 488 seconds.

Peak Overpressure: 6.22e+08 Pa = 6220 bars = 88400 psi

Max wind velocity: 20100 m/s = 44900 mph

Sound Intensity: 176 dB (Dangerously Loud)

Damage Description:

Multistory wall-bearing buildings will collapse.

Wood frame buildings will almost completely collapse.

Multistory steel-framed office-type buildings will suffer extreme frame distortion, incipient collapse.

Highway truss bridges will collapse.

Highway girder bridges will collapse.

Glass windows will shatter.

Cars and trucks will be largely displaced and grossly distorted and will require rebuilding before use.

Up to 90 percent of trees blown down; remainder stripped of branches and leaves.

Tell me more...

Click here for a pdf document that details the observations, assumptions, and equations upon which this program is based. It describes our approach to quantifying the important impact processes that might affect the people, buildings, and landscape in the vicinity of an impact event and discusses the uncertainty in our predictions. The processes included are: atmospheric entry, impact crater formation, fireball expansion and thermal radiation, ejecta deposition, seismic shaking, and the propagation of the atmospheric blast wave.

[Scribbler]

To sum it up:

Kaboom!!!

Bye bye world as we know it!

:blink:

[Rollo]

Whoops Apocalypse!

....

I will not sleep tonight after reading your post Pete,perhaps I should start digging a deep hole.

[Scribbler]

Rollo - click on that link and drop something on Inverness to get your own back! :blink:

[stratty]

Rollo - click on that link and drop something on Inverness to get your own back!

Hasn't some one done that already! :blink:

[Methuselah]

I will not sleep tonight after reading your post Pete,perhaps I should start digging a deep hole.

Oh dear! I meant 24000kph...

[Paranoid]

Well, hopefully we'll be able to see it before it's too close to use Nuclear weaponry, maybe the US could put it's arsenal to good use.

[osmposm]

Oh dear! I meant 24000kph...

Yes, I thought it was going a tad fast, Peter!

Mind you, I love that "the earth is not strongly disturbed by the impact..." - even by your half-a-kilometre wide rocket-propelled meteorite.....species may come, and species may go, but the earth will chug on regardless.

[SNOW-MAN2006]

Well, hopefully we'll be able to see it before it's too close to use Nuclear weaponry, maybe the US could put it's arsenal to good use.

nuclear bombing it would be the worst thing possible. a shower of radioactive dust particle floating about .... not very nice

however if we didnt use nuclear and used alot of bombs then possibly it would be big enough to blow it up

[Scribbler]

If you try to blow up a huge rock (say 1 km diameter or larger) even the broken bits will be lethal. And if they're radioactive as well..........!

If it just splits in half, for example, then you end up with two huge impacts. :blink:

I'm not saying that reducing it to much smaller bits wouldn't be a good idea but it might not be that simple.

Pushing it aside might be easier, assuming that we could get to it in time.