Effects of a huge asteroid collision with earth

oh, and an asteroid didnt wipe out the Dinos.

 

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Everyday the odds get better for an asteroid collision with earth. Everyday the odds get better that the Yellowstone Supervolcano will erupt soon. If an asteroid 1 mile or bigger impacted within 400 miles of Yellowstone, it could possibly cause it to erupt.........Better stock up now on cigarettes, bullets and beer!

Yob Atta

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Do you mean: every day people get more neurotically aware of the danger from asteroids, and thus the statisticians revise their estimates upwards?

I think the height of public hoopla about the danger of impacts was in the late 1990s, when Deep Impact and Armageddon were filmed. A lot of people were grasping for a new doomsday scenario to worry about, with the Cold War over.

Surely, as the Solar System ages, the supply of interplanetary debris will gradually diminsh. The odds of an asteroid collision with Earth should grow gradually poorer each day, not better.

 

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It's interesting to note that in the last five years the earth has several small asteroid "near misses", where we never even saw them or even knew they were there until they passed by the earth and was phtographed a day or two later. The same will probably happen when a bigger one decides bury itself in the middle of some same state or the ocean sometime in the not-to-distant future. Tell that to the odds makers........

Yob Atta

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Yea the chances of us seeing a giant asteroid coming is very slim. We do not track that much of outer space.

 

Would an asteroid hitting the ocean be a better prospect for humans than striking the land as it wouldn't create a huge dust cloud? The tidal waves would kill but its lasting effects wouldn't be global as a dust cloud would it?

 

It really depends on the size of the asteroid. If it's small ... like a few kilometers wide or under ... then the prospect for humans would be better if it smashed into the ocean. But if the asteroid is very large ... like hundreds of km wide ... then it really doesn't matter where it hits as it would vaporize the ocean almost instantaneously upon impact and still cause as much destruction as if it hit land.

 

but even if the ocean was vapourised wouldn't the water eventually condense and fall back as rain?

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The water cycle may become somewhat erratic with floods and drought but the pattern would remain the same I think. It wouldn't be as bad a dust cloud blocking out the sun and effecting the whole cycle and climatic temperatures.

 

The amount of energy released upon the imapct of a massive asteroid would be so intense that the surrounding atmospheric pattern and circulation would completely be negated. The water cycle would cease to exist in the surrounding area and anywhere as far as the resulting shockwave could reach.

 

Thats quite scary. What are the dynamics of the energy released affecting the atmosphere and subsequent water cycle? I mean how does it work? How would it cease to exist. Are there any links that go into this in more detail? thanks

 

To give you an an idea of how much energy is released during impact ... take a look at this site:

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

Enter any parameters you want and it will "calculate" various information about the resulting impact of the hypothesized asteroid. It's quite useful.

As for the dynamics ... its not so much the energy that is released that affects the atmosphere ... its the fact that upon impact, the air is pushed away at extremely high velocities (caused by the shockwave) and the surrounding ambient temperature increases from normal air temperature to thousands of degrees in a split of a second.

The atmosphere is primarily a delicate balance between temperature, pressure, air density, and humidity. These factors play an important role in weather and climate ... among other things. If one of those factors changes, then they all change until it is balanced again.

The water cycle requires that the air temperature be approximately -50C so that the water vapor accretes and falls as percipitation ... and that can be found in the upper troposphere. If an asteroid strikes either land or water, the ambient temperature increses to thousands of degrees in a blink of an eye and the conditions for precipitation is no longer there. This causes the water cycle to "cease to exist" and this effect cannot be reversed so quickly since the shockwave produced by the impact would disrupt all air circulation throughout the atmosphere. Other factors which change drammatically are air pressure and humidity.

I'm not sure about any links about this ... I'm stating this from what I know so far about atmospheric dynamics so it may be subject to corrections.

 

Talking of waves and things, if a nearby star were to explode, would that send ripples of gravity waves through space and what would happen if we were to be hit by a giant gravity wave ?

 

A nearby star exploding... it would depend HOW nearby. None of our neighbours nearer than Vega (about 26 light years away) are massive enough to be likely to explode.

Even then, the gravitational radiation emmitted would be nothing of any consequence. The main effects would be electromagnetic radiation, with a high gamma- and X-ray flux which could have serious consequences for biology - and might also severely damage the ozone layer. The supernova would not have any direct effect on our climate, however, as its heat output would be harmlessly gentled by distance. Even if Alpha Centauri A, only 4.3 light years away, were to explode, it would still send us barely 1% of the heat and light we receive from the Sun.

@Starsky & The Singularity: an impact in the ocean by an object a few miles wide would vapourise so much water that the whole Earth could be completely cloud-covered for months. That would lower the temperature just as effectively as a land-derived dust cloud. Plus, the ocean impact could still trigger forest fires on any landmass within hundreds of miles, and still produce a devastating rain of ejecta which would be blasted out of the ocean floor. Even the deepest parts of the sea are insufficient to stop a sizeable impactor before it connects with the bottom: in fact, the blast would literally open a hole in the ocean, exposing the seabed to the sky for a radius of dozens of miles. The water would return pretty quickly, of course.

 

After looking into the matter of large scale asteroid impacts further ... I would have to change my point of view slightly on the subject. Frankly, what I mostly knew about asteroid collisions are from those end-of-the-world movies and media reports ... and I just connected that to what I already knew about it. Not the best thing to do considering I'm a "scientist in training"

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Some of what I said is true ... but concerning the climatic impact of a large scale asteroid, smashing into the ocean would limit atmospheric alterations since it's mostly vaporized water that's being ejected into the atmosphere. Though I don't know if the resultant clouds would fall back as rain ... maybe not immediately.

 

Oh well, we could change it a bit for the movie though !

 

What if a 3 to 6 mile wide asteroid impacted in the middle of Yellowstone park or even within a radius of 400 hundred miles of it. I'm sure that would setup a chain of events which would be enough to make the world's largest supervolcano erupt with a force of 10,000 to 15,000 volcanos erupting at the same time. It's already 40,000 years overdue!!! I'm sure it would be an even larger eruption than what TOBA was 74,000 years ago........And with the asteroid impacting nearby, so long McDonalds!!!

Yob Atta

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OH no not mcdonalds~~~ I love mcdonals i eat it every day. Trust me the chances of a asteroid hitting in yellowstone park are almost 0. NOrman u seem to be obsessed with that yellowstone super volcano. Anywayz back on topic. Say a asteroid did hit like north america or something the size of dallas or something and put the whole earth into darkness? How long could we last?

 

I hate to say it, but in terms of where an asteroid hits on earth, there is no such thing as the word "zero".........An asteroid can hit anywhere, at anytime and there is no way to predict when it comes to asteroid impacts unless you have time to predict. In the past several years, we have had several near misses by small asteroids where we didn't even know they had just passed between the earth and moon until they were photographed one or two days later. That's a fact! So forget the term "0"...........

Yob Atta

 

If you had a hideaway strong enough, and lucky enough, to survive the immediate global devastation, you'd last as long as your supply of fuel, food and fresh water held out. If you could avoid starvation or freezing to death for 2-4 years, you could come out and start farming again. I wouldn't expect very good harvests for the next few years, however.

 

I'll start stocking up on egg plants and a few cases of beer just in case the big one hits in the next year or two.........

Yob Atta