Elenin spotted

Originally posted by galactix
important to understand that it is not the expected behavior, thats all.

I disagree,

By definition, comets are almost always breaking up. Comets have tails (when they are in the inner solar-system), and those tails would not be there without the comet breaking up. A tail is what sets comets apart from just a plain old asteroid.


As was pointed out, there are many meteor showers... which come from comets as they break up.

The degree to which a comet is breaking up depends on two main factors:

1/ How close it gets to the sun.
2/ How close it gets to the gravitational fields of other large solar system bodies.

Also to an extent it will depend on the composition/structural integrity of the comet, and it's possible that meteoroid impacts could also have a significant effect.

Someone earlier suggested that Shoemaker-Levy 9 broke up due the sun, but that is wrong. It broke up because it got too close to Jupiter's massive gravitational field.

Calculations showed that its unusual fragmented form was due to a previous closer approach to Jupiter in July 1992. At that time, the orbit of Shoemaker–Levy 9 passed within Jupiter's Roche limit, and Jupiter's tidal forces had acted to pull the comet apart. The comet was later observed as a series of fragments ranging up to 2 km (1.2 mi) in diameter.

wikipedia

Comet Holmes was a completely different scenario all together. The cause of the outburst has never been conclusively established. There are a few possible explanations for the outburst.

Whatever the cause was, it only bolsters the argument that comets are fragile and prone to break up, or even disintegration in some cases.

One other thing that no one else here has mentioned, is that cometary meteor showers have been well studied and many meteors photographed. From the photographs we can tell that cometary meteoroids are generally significantly less dense and fragile than their asteroid counterparts.

Based upon photographic fireball studies, cometary meteoroids have extremely low densities, about 0.8 grams/cc for class IIIA fireballs, and 0.3 grams/cc for class IIIB fireballs. This composition is very fragile and vaporizes so readily when entering the atmosphere, that it is called “friable” material. These meteoroids have virtually no chance of making it to the ground unless an extremely large piece of the comet enters the atmosphere, in which case it would very likely explode at some point in its flight, due to mechanical and thermal stresses.

American Meteor Society

I've seen this for myself many times with cometary meteors, and they are usually easy to tell apart from asteroidal meteors - a bit like throwing a loose/non-compacted hand-full of soil versus a moist and compacted hand-full of soil into the water.

That is not to say that there may be exceptions to this "rule", as can be found throughout nature, but we have lots of evidence that suggests that most comets are made of fragile material that easily breaks up under thermal and/or gravitational stress.

Originally posted by Illustronic
reply to post by Greensage

 

Nope, Elenin crosses the earth orbital plane markedly above, we will never go through the trajectory of the orbital path of said distinguished extinguished comet. It crossed our orbital plane inside our orbit, so below on one side above on the other.

Dark blue means below, light blue means above. Not even close.

That may not quite true. I know of at least one researcher who thinks there is a chance we might see meteor showers from Elenin in years to come.

I usually search for new possible meteor showers from newly
discovered comets, I saw too this one but I think that until the
comet has a eccentricity of more of 1 there isn't a meteor shower
(in this special case it can to be two meteor showers, one in the night
and one in the day) the better new it's that IHMO the comet can
to be periodic with a period in resonance with one of the esternal
planets (it's only a possibility), if it's true then it's possible that
there
is a meteor shower linked with P/2010 X1 (I wrote P/, but now it's C/)
in this case we shall see the meteors in the next years.
But at today it's only a hope.
Best greetings.
Roberto Gorelli

METEOROBS (The Meteor Observing mailing list)

That was posted some time ago, so things may have changed since then. I think we are still waiting for a thorough modeling of Elenin's meteoroid stream. Even though a meteoroid stream lies away from Earth's orbit, gravitational perturbations by Jupiter especially as well as the solar wind can push meteoroids into Earth's path given time.

Edit to add - If there is a meteor shower due to meteoroids from Elenin, there is no reason to think that it will any different to any other meteor shower Earth encounters at the moment or in past history. There may well be small quantities of poisonous gas, but gas is light, so it is the first thing swept away and dispersed by the solar wind. Larger (dust and above) sized meteoroids, are not as easily moved by the solar wind, so they are left behind, possibly to give us a meteor shower.

Originally posted by galactix

Originally posted by Illustronic
a cloud 40' by 6'!

those are arc minutes..u ignoramus.

if u knew math you might be able to calculate the actual size, but math is probably beyond you, eh?


fool.

So tell us Einstein, how big is it then?

Originally posted by galactix
wrong.
most comets do NOT disintegrate.

I never said that "most comets" disintegrate. Show me in my original quote were I said that and I will give you $1 million. I said that they "sometimes break up" and I said that comets disintegrating was "pretty common," and the source of the various meteor showers we periodically experience throughout the year.

Different comets have different ends to their lifespans. I don't know the percentage that just slowly evaporate over the eons vs. those that plunge into the Sun vs. those that hit Jupiter, the Earth or other planets. But, comets don't last forever. Eventually have have to either hit something or they evaporate into nothing by the periodic heating they experience when coming close to the Sun. But their death is inevitable.

Originally posted by C.H.U.D.
Someone earlier suggested that Shoemaker-Levy 9 broke up due the sun, but that is wrong. It broke up because it got too close to Jupiter's massive gravitational field.

Actually, I did not say it was the Sun that caused it to break up, though the way I worded it I can see why you may have thought that (I mentioned "other conditions" in that sentence in part for that reason). I actually was aware that it was an earlier pass with Jupiter's gravity that caused its break-up.

reply to post by LifeInDeath


Yes, That's a fair comment. I should not have said you were wrong after re-reading what you said.

Originally posted by C.H.U.D.

By definition, comets are almost always breaking up. Comets have tails (when they are in the inner solar-system), and those tails would not be there without the comet breaking up. A tail is what sets comets apart from just a plain old asteroid.

If tails are indeed created by out gassing 'iceballs' then, yes, they (the comets) are 'breaking up' constantly. IF they are ou tgassing... this has not been proved, nor do our recent data support that hypothesis. Comets have tails out past Jupiter. Jupiter is the inner system?

I'm pretty sure it's orbit that sets asteroids and comets apart. Asteroids have largely circular orbits and comets highly elliptical orbits. Something about the fact that when a body changes it's radial distance from Sol (as in highly elliptical orbits) these bodies acquire a tail and coma.

Every physical sampling of comets or meteors (stuff in cometary orbits) has organic compounds present. I do not buy the iceball hypothesis.

As was pointed out, there are many meteor showers... which come from comets as they break up.

How do these comets keep producing meteor shower after meteor shower year after millennial year and still exist?

Whatever the cause was, it only bolsters the argument that comets are fragile and prone to break up, or even disintegration in some cases.

There are thousands of known comets (much less unknown ones) and we can count a few that disintegrate. This implies nothing at all about comets in general. Some humans are dwarfs. I can count a few. This fact says nothing about average human physiology.

One other thing that no one else here has mentioned, is that cometary meteor showers have been well studied and many meteors photographed. From the photographs we can tell that cometary meteoroids are generally significantly less dense and fragile than their asteroid counterparts.

'have been well studied'. yah. uselessly. if u saw how abysmally these studies and their resultant models predicted the last few meteor showers, you wouldn't bring them (the studies) up as a point to lean on.

and/or gravitational stress.

The solar system is electrically neutral then? Can you prove this?
Common, guyz! Cassini has SEEN the huge currents passing between gas giants and their moons.

sheesh.

Originally posted by Chamberf=6

So tell us Einstein, how big is it then?

it's not how big it is that matters, it's the fact that the lad didn't even understand the units being used.

and his flippant response warranted an extra 'jab' in my opinion.

when i have made my own observations, i shall post my data and calcs for you guyz to comment on. i trust my own rulers, thankyouverymuch.

Originally posted by LifeInDeath
I said that comets disintegrating was "pretty common," and the source of the various meteor showers we periodically experience throughout the year.

i dunno, bro : "pretty common" and 'most' are only fractionally different..and "most" is only one word with four letters... easier to type.

Dood, comets are only commonly 'breaking up' if, in fact, comas, tails, and meteors are produced by comets. this is not a fact. this is a hypothosis. not proven.

you can build only faulty logic on incorrect primary assumptions.

If tails are indeed created by out gassing 'iceballs' then, yes, they (the comets) are 'breaking up' constantly. IF they are ou tgassing... this has not been proved

Is kind of proven. What kind of proof do you need for confirmation? Would asteroid without tails prove anything to you? How about extinguished comets (they exist) where all of their frozen gaseous substance had expired?

Nobody is saying all comets are ice and dirt. What we are saying is long term comets rarely get close to the sun and the effects of the gravitational force, the speed, and the fact even metal would be frozen and Sublimation straight to the gas without forming a liquid in between makes comets more likely to be of tenuous composition much different from asteroids that have existed in the area that cause comets outgass. Asteroids have long ago been solid while some comets never are by inner solar system standards.

Originally posted by Illustronic

Is kind of proven. What kind of proof do you need for confirmation?

not even close to proven.
confirmation = data.
We've been to two comets, with probes, and sampled meteor matter entering our atmosphere. The comets had essentially zero water and were made of very very black very very fine ORGANIC MATERIAL and were totally quiet; no off gassing. This in no way supports the iceball theory. These data, in fact, refute this theroy in my opinion.

meteor matter is ORGANIC!

reply to post by galactix


No outgassing? The impact crater from Deep Impact alone outgassed for 13 days during which 11 million pounds of water was released. What was surprising about the results was not that there was little water, but that there was less water than expected. Scientists thought that frozen water would be present on the surface, but instead it seemed to be most contained under the surface. From these results the only model that could be discarded regarding the structure of comets is that they were composed of porous material.

reply to post by galactix


Do you need a sample of every comet to prove a theory? Do you really or would one find enough supporting data to confirm the compositions of what spectrometer signals are detected. Do you know how that even works?

Originally posted by galactix

I'm pretty sure it's orbit that sets asteroids and comets apart. Asteroids have largely circular orbits and comets highly elliptical orbits. Something about the fact that when a body changes it's radial distance from Sol (as in highly elliptical orbits) these bodies acquire a tail and coma.

Every physical sampling of comets or meteors (stuff in cometary orbits) has organic compounds present. I do not buy the iceball hypothesis.

When the solar system formed, all the rocky stuff was in the inner area, this is where planets and asteroids formed, while further out where is was cooler, past mars, it was cool enough for water to freeze and that's we get our comets forming. As they come closer to the sun during their orbit, they warm up and start shedding material which is where we get the tail, and yes, it can reach well past Jupiter. You are right about the orbits though.

How do these comets keep producing meteor shower after meteor shower year after millennial year and still exist?

Because you have to remember that your average meteor during a shower is no bigger than a grain of sand, and each year we pass through a different section of the material, left behind.... there is lots of it up there.

Originally posted by Xcalibur254
reply to post by galactix

 

No outgassing? The impact crater from Deep Impact alone outgassed for 13 days during which 11 million pounds of water was released.

from same wiki article:
"In addition, the material was finer than expected; scientists compared it to talcum powder rather than sand.[37] Other materials found while studying the impact included clays, carbonates, sodium, and crystalline silicates which were found by studying the spectroscopy of the impact.[12] Clays and carbonates usually require liquid water to form and sodium is rare in space."

requires liquid water: liquid!

"A total of 5 million kilograms (11 million pounds) of water and between 10 and 25 million kilograms (22 and 55 million pounds) of dust were lost from the impact"

between 10 and 25 million kilograms...not to sure of their estimates then are they? and even still that's a small percentage of the actual stuff that blew out of the impact site.

and finally: out gassed after impact. not before.

"outgassing from the impact for 13 days, with a peak five days after impact" 13 days is not too long when u slam a huge kinetic missile at a porous structure. I read accounts where some scientists expressed surprise at how quickly the comet became quiet again.

quite again.

tell me again how a comet produces a coma larger than Jupiter? and tails many times that volume.

where does on that stuff come from when the comet is so dern quiet.

still not buying it.

reply to post by galactix


I'm also not sure what they were referring to what you call organic. It was minute particles of a simple structure that makes up RNA, Glycine, one of many substructures of simple protein by itself is no more important than sugar, and in no way suggests life or space creatures. They found one of the thousands of chemicals that support life as we know it and it's almost like saying that hydrogen, and oxygen which are two of the 3 most abundant elements in the universe followed by carbon which is the 6th most abundant element is 'organic' is ludicrous!

It was and is a chemical by itself, and nothing more. Glycine.

reply to post by galactix


You have to remember that the water/ice once turned to gas occupies a much greater space, and it only leaves the comet once it is close enough to the sun for the solar winds and particles to start having an effect, once it moves away it stops releasing material.

Originally posted by woogleuk

When the solar system formed, all the rocky stuff was in the inner area, this is where planets and asteroids formed, while further out where is was cooler, past mars, it was cool enough for water to freeze and that's we get our comets forming.

yes yes, we've all read this stuff. again, this is hypothosis not fact.

Facts are : "measure organic material". "calculated sizes based on minutes of arc". "presence of OH radicals measured by radio telescopes", "imaged huge electric currents passing between Uranus and it's moons" , "measured presence of huge magnetic fields beyond the ort cloud"

none of which support current hypothesis

We have not actually seen a solar system forming accretion disc with our instruments. We have seen a bunch of inexplicable brown dwarfs hanging out all alone like tho... sans dust and stuff, no less.

curious, eh?

reply to post by galactix


That 'stuff' is sparser than the best vacuum we can make on earth, it is space particles highly light reflective and people call it mass, it is minute fine nothing that reflects light from the sun. Not anything magical, or electrical, or of intelligence. Just very fine dust spread out very far and very sparsely. You are just viewing it from very far away.

reply to post by galactix


Still waiting on those calculations of the size, Einstein.