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Christine112
2001-Dec-11, 03:32 PM
If there are so many meteorites that enter Earth's atmosphere, then why don't we see rocks falling from the sky?

2001-Dec-11, 04:07 PM
Actually christine meteorites are falling all the time. in fact every year annually three to four hundred people are killed by meteorites, including the countless numbers of dogs and cats. however these events are covered up by the mysterious shadow government in order to prolong their war with the space marines from saturn who throw these meteorites at us from their huge death ray.

Also check out crab nebula the movie starrin Dustin Hoffman

SeanF
2001-Dec-11, 04:47 PM
Oh, Fred, you've said too much -- now we have to kill you.

Seriously, Christine, the reason we don't see so many rocks falling from the sky is because there aren't all that many meteorites. There are, however, a lot of meteors.

Most of the meteors, though, burn up in the atmosphere and are essentially disintigrated before they get anywhere near the ground. Those are the bright streaks you see in the sky during meteor showers.

The few meteors that do make it to the Earth's surface more or less intact are called "meteorites". They are, obviously, much rarer than meteors.

Hope this helps!

Now, Fred, come with me, please . . .


_________________
SeanF

<font size=-1>[ This Message was edited by: SeanF on 2001-12-11 11:48 ]</font>

ToSeek
2001-Dec-11, 07:36 PM
On 2001-12-11 10:32, Christine112 wrote:
If there are so many meteorites that enter Earth's atmosphere, then why don't we see rocks falling from the sky?


Keep in mind that most of the meteors making streaks in the sky are marble-sized or smaller. They're much too small not to burn up before reaching the ground.

DStahl
2001-Dec-11, 08:40 PM
Absolutely in agreement with previous posts--nearly all chunks of space rock and ice vaporize as they zoom into Earth's atmosphere. But I might note that even these vaporized bits add to Earth's mass (where else would the vaporized silicon and iron and such go but here?) and so they don't just disappear. Eventually I suppose the remains settle to Earth as microscopic bits, perhaps washed from the sky in raindrops. Anyone got some hard data on this?

--Don

ToSeek
2001-Dec-11, 09:03 PM
"Scientists estimate that 1,000 tons to more than 10,000 tons of meteoritic material falls on the Earth each day."

- http://space.about.com/library/solarsys/blmeteorinfo.htm

ToSeek
2001-Dec-11, 09:04 PM
Another viewpoint:

"The dust may add roughly 100 tonnes per day to the mass of the Earth."

- http://www.science.uwaterloo.ca/earth/waton/f995.html

Kaptain K
2001-Dec-11, 09:06 PM
Anyone got some hard data on this?
No, but if you want to collect some, wrap a magnet in cling wrap and put it on the roof for a few weeks. Unwrap it over a piece of white paper. You should have a small accumulation of iron dust, some (most?) of which will be meteor dust.

ToSeek
2001-Dec-11, 09:27 PM
On 2001-12-11 16:06, Kaptain K wrote:
No, but if you want to collect some, wrap a magnet in cling wrap and put it on the roof for a few weeks. Unwrap it over a piece of white paper. You should have a small accumulation of iron dust, some (most?) of which will be meteor dust.


And then sell it on Ebay! /phpBB/images/smiles/icon_wink.gif

DStahl
2001-Dec-13, 09:14 AM
Hey, Kaptain K, that is a Kool idea! I'm a gonna try this one. Thanks!

--Don

Manchurian Taikonaut
2004-Mar-14, 09:34 PM
Yes, we get some wonderful images from comets and meteorites. If any of those 1km size rocks were ever to hit Earth you can say goodbye. Most think the dinosaurs died out because of this....

There are lots of projects and future plans to study these wonders of space, some from Asia, Russia, NASA and some comet chasers being uilt in Europe also.

LINK (http://energy.phys.ncku.edu.tw/~astrolab/mirrors/apod/image/0105/halebopp5_aac_big.jpg)

cyswxman
2004-Mar-14, 10:04 PM
ToSeek[/b]]Another viewpoint:

"The dust may add roughly 100 tonnes per day to the mass of the Earth."

- http://www.science.uwaterloo.ca/earth/waton/f995.html

That sounded like a decent amount, until I did some math. That comes out to approximately 7 micrograms per square meter, per year, assuming equal distribution over the surface of the Earth.

Kaptain K
2004-Mar-14, 11:51 PM
...If any of those 1km size rocks were ever to hit Earth you can say goodbye. Most think the dinosaurs died out because of this...
The rock that killed the dinosaurs was on the order of 10 kilometers in diameter. A 1 Km rock would be a disaster, but it would not wipe us out. A 100 Km rock would pretty much sterilize the planet (99+% of multicellular life).

Manchurian Taikonaut
2004-Mar-15, 12:09 AM
Maybe a 1Km rock wouldn't destory us like the dinosaurs went however.We must admit that a 1 Km rock could end our way of life, it has the ability to kill many people, it could destroy nations, and disrupt the life, people and economies, and the worlds climate would maybe also face changed also. Our old lifestyles would be gone, rouge organisations might try to get control.
If it hit near a populated area then the impact and devestation on mankind would be greater. Although it is a horrible event, some impacts have been wonderful and amazing.

http://www.meteorpassion.com/meteor/photo/jupi.jpg


A 100Km rock? That's horrible :o . I'd hate to think these types of rock come whizzing by the Earth. Kaptain K, do we have any plans on how do deal with such an event? #-o Or do we already know how to stop them?

Kaptain K
2004-Mar-15, 12:43 AM
I agree that a 1Km rock would be devastating. It would kill tens to hundreds of millions (depending on where it hit). Hundreds of millions to billions would die in the aftermath. Modern, "civilized" life as we know it would come to an end. If enough information survived, perhaps the climb back would not be as long and arduous.


...do we have any plans on how do deal with such an event? Or do we already know how to stop them?
No and no!

milli360
2004-Mar-15, 05:30 AM
That sounded like a decent amount, until I did some math. That comes out to approximately 7 micrograms per square meter, per year, assuming equal distribution over the surface of the Earth.
When I was ten years old, my elementary school teacher found an activity, and suggested we set out pie tins in the back yard during meteor shower times. Overnight, a bit of dust accumulated, and it was magnetic. It was thought to be meteoric.

Brady Yoon
2004-Mar-15, 06:08 AM
Actually christine meteorites are falling all the time. in fact every year annually three to four hundred people are killed by meteorites, including the countless numbers of dogs and cats. however these events are covered up by the mysterious shadow government in order to prolong their war with the space marines from saturn who throw these meteorites at us from their huge death ray.[quote]
400 people killed by meteorites per day? Every year that's 14,600 people! Surely someone would notice!!! :D It's probably more like 1 death per century some one is killed by a meteorite. Very rare.

Brady Yoon
2004-Mar-15, 06:11 AM
from the previous posts, i was wondering

The rock that killed the dinosaurs was on the order of 10 kilometers in diameter. A 1 Km rock would be a disaster, but it would not wipe us out. A 100 Km rock would pretty much sterilize the planet (99+% of multicellular life).
would the 100 km rock sterilize 99% of the planet immediately or after the long-term affects are over with. And has a 100 km rock every struck earth before?

Manchurian Taikonaut
2004-Mar-15, 02:49 PM
picture of Rosetta project
http://www.universetoday.com/am/uploads/2004-0311rosetta-lg.jpg

Russ
2004-Mar-15, 11:58 PM
from the previous posts, i was wondering

The rock that killed the dinosaurs was on the order of 10 kilometers in diameter. A 1 Km rock would be a disaster, but it would not wipe us out. A 100 Km rock would pretty much sterilize the planet (99+% of multicellular life).
would the 100 km rock sterilize 99% of the planet immediately or after the long-term affects are over with. And has a 100 km rock every struck earth before?
It would take about 6 months to wipe out most of the multi-cellular life. The scavengers would live off the dead until they froze from falling global temperature.

Nobody knows if a 100km anything has hit Earth since life evolved past singel cell life. There was a mass extinction about 265 million years ago but that has not been tied to any particular event. It could well have been a huge rock. :)