Small Comet bombardment of Earth! - Page 2

RecoveringYuppy · 26th February 2008, 08:59 AM

Originally Posted by BeAChooser

So what's the probability of the space station being hit during its life by one of these?

Originally Posted by Dancing David

I don't know take the surface area of the space station, devide by the surface area of the earth's atmosphere and fudge for gravitational attraction.

The space station is more likely to get holed by space junk, especially stuff that escapes from the station.

If I suppose the space station to be five hundred feet (a tenth of a mile) across it has a cross section of 1/100 square miles. The cross section of the Earth is about 50 million square miles. So, not fudging for gravity, the station is 5 billion times less likely to be hit.

If I assume that the Earth being hit "every couple of seconds" works out to 40,000 hits a day or 14.6 million a year.

So the station would be hit once every 300 years or so.

That's assuming these things survive to the altitude of the space station.

BenBurch · 26th February 2008, 09:15 AM

Originally Posted by RecoveringYuppy

How do you know they would contain solids? Especially buckshot sized?

All comets we have looked at in detail have been of the "dirty snowball" model, and some appear to have a crust that almost totally covers the internal ice. But we knew there were solids long ago as there are two tails to almost any comet; The gas tail and the dust tail, and many meteor showers are associated with current and extinct periodic comets. And I did not mean buckshot sized; at those speeds a grain of sand has more energy in it than a 00 buckshot taken at close range.

And if I recall correctly, the Mir space station was hit by a micrometeorite during a known meteor shower, and it blew a fist-sized hole through one of the solar panels. And Endeavor had one of its windows hit.

robinson · 26th February 2008, 01:07 PM

I'm still wondering about this figure.

Originally Posted by BenBurch

As pointed out above, it DOES get bigger over time. About 50 tons a day of in-falling meteoric material.

50 tons a day of solid meteoric material. Where does that come from? How come it doesn't hit satellites, shuttles, the space station? How come we don't see it hitting the moon?

Fluffy ice balls that turn to water vapor 600 miles out I can almost believe, but 50 tons of rock and metal every day? What is that all about?

BenBurch · 26th February 2008, 04:14 PM

That is based on radio and visual observations of infall rates, and data from the Pegasus satellite and high-altitude aircraft dust capturing missions.

The trouble with fluffy iceballs is that they do not exist.

26th February 2008, 08:59 AM	#41
RecoveringYuppy Illuminator Join Date: Nov 2006 Location: Tucson, AZ Posts: 3,851	Originally Posted by BeAChooser So what's the probability of the space station being hit during its life by one of these? Originally Posted by Dancing David I don't know take the surface area of the space station, devide by the surface area of the earth's atmosphere and fudge for gravitational attraction. The space station is more likely to get holed by space junk, especially stuff that escapes from the station. If I suppose the space station to be five hundred feet (a tenth of a mile) across it has a cross section of 1/100 square miles. The cross section of the Earth is about 50 million square miles. So, not fudging for gravity, the station is 5 billion times less likely to be hit. If I assume that the Earth being hit "every couple of seconds" works out to 40,000 hits a day or 14.6 million a year. So the station would be hit once every 300 years or so. That's assuming these things survive to the altitude of the space station.
	__________________ REJ (Robert E Jones) posting anonymously under my real name for 30 years. Make a fire for a man and you keep him warm for a day. Set him on fire and you keep him warm for the rest of his life. Last edited by RecoveringYuppy; 26th February 2008 at 09:00 AM.

26th February 2008, 09:15 AM	#42
BenBurch Gatekeeper of The Left Join Date: Sep 2007 Location: The Universe 35.2 ms ahead of this one. Posts: 32,177	Originally Posted by RecoveringYuppy How do you know they would contain solids? Especially buckshot sized? All comets we have looked at in detail have been of the "dirty snowball" model, and some appear to have a crust that almost totally covers the internal ice. But we knew there were solids long ago as there are two tails to almost any comet; The gas tail and the dust tail, and many meteor showers are associated with current and extinct periodic comets. And I did not mean buckshot sized; at those speeds a grain of sand has more energy in it than a 00 buckshot taken at close range. And if I recall correctly, the Mir space station was hit by a micrometeorite during a known meteor shower, and it blew a fist-sized hole through one of the solar panels. And Endeavor had one of its windows hit.
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26th February 2008, 01:07 PM	#43
robinson Banned Join Date: Aug 2006 Posts: 6,136	I'm still wondering about this figure. Originally Posted by BenBurch As pointed out above, it DOES get bigger over time. About 50 tons a day of in-falling meteoric material. 50 tons a day of solid meteoric material. Where does that come from? How come it doesn't hit satellites, shuttles, the space station? How come we don't see it hitting the moon? Fluffy ice balls that turn to water vapor 600 miles out I can almost believe, but 50 tons of rock and metal every day? What is that all about?
robinson Banned Join Date: Aug 2006 Posts: 6,136

26th February 2008, 04:14 PM	#44
BenBurch Gatekeeper of The Left Join Date: Sep 2007 Location: The Universe 35.2 ms ahead of this one. Posts: 32,177	That is based on radio and visual observations of infall rates, and data from the Pegasus satellite and high-altitude aircraft dust capturing missions. The trouble with fluffy iceballs is that they do not exist.
	__________________ Are you IN? Join the IN crowd now! Last edited by BenBurch; 26th February 2008 at 04:14 PM.