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Fraser
2006-Apr-05, 03:55 AM
SUMMARY: When Deep Impact collided with Tempel 1, it released an amazing amount of water vapour from the comet - as much as 250,000 tonnes were blasted into space. These measurements were made by NASA's Swift satellite, which normally locates and observes gamma ray bursts. Swift, like almost every other telescope on Earth and in space was pointed at Comet Tempel 1 when Deep Impact smashed into it last July. Swift monitored the X-ray emissions before and after the collision, and used that to measure the amount of water vapour ejected.

View full article (http://www.universetoday.com/am/publish/250_000_water_tonnes.html)
What do you think about this story? post your comments below.

antoniseb
2006-Apr-05, 11:47 AM
I wish I undersood what the data analysis of this required. This would be very nice information to have had nine months ago. There's been a lot of perhaps useless discussion about what it means to have mostly dry comets in the mean time.

VanderL
2006-Apr-05, 03:18 PM
I wish I undersood what the data analysis of this required. This would be very nice information to have had nine months ago. There's been a lot of perhaps useless discussion about what it means to have mostly dry comets in the mean time.

It sure goes against most of what has been published until now, I'm curious as to how X-rays can be used to measure water concentrations. It seems a rather difficult process, and an unfamiliar (to me at least) mechanism. What I'm missing in their story is whether the impact itself produced any X-ray peak.

Cheers.

antoniseb
2006-Apr-05, 03:41 PM
What I'm missing in their story is whether the impact itself produced any X-ray peak.

X-Rays from impact would last milliseconds. These xrays lasted several days.

VanderL
2006-Apr-05, 04:13 PM
X-Rays from impact would last milliseconds. These xrays lasted several days.

So it would seem, but I didn't see any plot with X-ray data, I was wondering whether the initial peak (which would be expected) was there or not. The prolonged X-ray emission was certainly a surprise, and I never heard of water measurements using X-rays before, did you?

Cheers.

antoniseb
2006-Apr-05, 04:31 PM
The prolonged X-ray emission was certainly a surprise, and I never heard of water measurements using X-rays before, did you?

Comets weren't my specialty, but I do recall years ago reading studies of xrays from comets. I didn't pay much attention to the cause, but was aware that it was from solar radiation of some sort hitting the material in the coma. Was it water? I wasn't paying attention. Looking for stories about this? Look at stuff about Hale-Bopp.

Jakenorrish
2006-Apr-05, 04:44 PM
The x-rays are produced when water particles interact with the solar wind, thus we can measure the water by the xray data. The peak measurement was 5 days after impact. Not that I knew any of this before this morning of course!!

http://news.bbc.co.uk/1/hi/sci/tech/4871934.stm

Jerry
2006-Apr-05, 09:26 PM
I'm not impressed. They claim to be able to subtract out the variations in the solar wind:

The X-ray power output depends on both the water production rate from the comet and the flux of subatomic particles streaming out of the Sun as the solar wind. Using data from the ACE satellite, which constantly monitors the solar wind, the Swift team managed to calculate the solar wind flux at the comet during the X-ray outburst. This enabled them to disentangle the two components responsible for the X-ray emission.


What I would like to know is, how they determined what the status of the solar wind is at the location of Tempel 1? I can see at least two variables and two unknowns: The solar wind flux at any location other than in a direct line with, and close to, the satellite is only a guess. Why didn't any of the many the direct observations pick this up? The simple answer is the multivariable extrapolation is wrong. I would love to see the raw data on this one!

Gerald Lukaniuk
2006-Apr-05, 10:32 PM
I love this forum’s constructive skepticism
"We got a lot of data that really does support the model" is from the article. It is scary how we keep getting this kind of PR from Space Scientists. In addition, how often they are surprised to find something are of a huge magnitude but fits the theory with no further explanation. We all "pays our nickel" but it must be hard on other researchers who now want to be constructive.
Some info about perhaps left over fuel, or possible secondary chemical reactions of the materials in the probe would be interesting..
I would be hugely excited if there was an elusion to a small delayed explosive device and I am disappointed because there should have been one. In addition, I do not recall if there was small test probe collision for comparison. Even a shotgun type burst would have made this a better experiment and less like a turkey shoot,
For instance, we know sugar powder dissolves faster than a cube so why was not this scenario predicted for solar wind in their model in a way that did not surprise them. Alternatively, is it the same scenario they did predict but their methods calibration need to be reassessed when instruments are put in space?
Maybe we are seeing a magnification phenomenon that solves many deep space riddles.
Are we seeing a delayed "chaotic equilibrium effect"? Does this happen in space frequently even though there’s no hint on earth like dark matter?
A physicist friend of mine for instance blew up his lab doing a high ionization upper atmosphere gas-water inter action experiment with titanium structures that was of course unexpected in its magnitude. The “good” science of picking up the pieces is reduced when there are “bad pieces” we cannot touch.

Gerald Lukaniuk
2006-Apr-05, 11:00 PM
On earth x ray are produced electrons hitting metal foil not steam. The probe vaporized metallizing the surface and increasing x ray production not water vapour. It may also of darkened it increasing the later due to infra red effects.

antoniseb
2006-Apr-05, 11:17 PM
The probe vaporized metallizing the surface and increasing x ray production not water vapour. It may also of darkened it increasing the later due to infra red effects.

If this is true, why did the xrays build up and then die down? What energy xrays to you think the copper-metalized surface should emit?

Gerald Lukaniuk
2006-Apr-06, 12:18 AM
If this is true, why did the xrays build up and then die down? What energy xrays to you think the copper-metalized surface should emit?
Layers only need to be atoms thin. Copper is extremely ductile,alloys can be formed that are even more so. Gold and silver are used also. An oz of gold makes sq miles of foil. Tumbling effects might account for variances. No jokes about pins though.

Gerald Lukaniuk
2006-Apr-06, 04:37 AM
Metal "tinsel" may have taken time to float to the surface. Surface tensions vs Gravity is a factor. Eventually perculating effect would churn up material until a layer of "crud" slowed it down. I've seen this with aluminum dust in a drop of water. It don't think punching a hole in prexisting coating can be ruled out entirely. The answers are in the wavelenghts.

tadowe
2006-Apr-06, 05:50 AM
Can someone point me to the experiments where x-rays have been produced from ionized water? Thanks.

sol88
2006-Apr-06, 07:13 AM
Adds a little more weight to EU model IMHO :eh:

Not suprising results from a certain models predictions :whistle:



Can someone point me to the experiments where x-rays have been produced from ionized water? Thanks.

I'd be interested as well :think:

Sol

tadowe
2006-Apr-06, 08:24 AM
I'd be interested as well
Sol

The Earth, itself, is one vast H2O experiment trying to generate x-rays from ionized water with interaction of the solar "wind." I don't think the "theory" has been proven true -- to date. Yet, this is the explanation from "science" as to the reason for the vast explosion and generation of x-rays from the Impactor on Tempel1?

. . . and they mock Arp, et al?

Jakenorrish
2006-Apr-06, 08:33 AM
The surprising thing for me is the peak measurement was after five days had elapsed. Anyone got any ideas as to why this was?

Tim Thompson
2006-Apr-06, 03:02 PM
Surely it is now time to move the entire thread to the ATM section? Once again, another severe bout of "science by press release". All we know is what some press agent wrote in a PR, and all of a sudden the foundations of science tremble? I don't think so.

First, here is a nice, recent, 103 page review of the physics of X-ray and EUV emission from comets, which covers all of the known mechanisms. Unfortunately, the paper itself is not available online, only the abstract. So you have to go find Space Science Reviews the old fashioned way. But of course, anyone who is seriously interested will do that.



X-Ray and extreme ultraviolet emissions from comets (http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=2004SSRv..113..271K&db_key=AST&d ata_type=HTML&format=&high=4366fa465131189)
Krasnopolsky, Greenwood & Stancil
Space Science Reviews 113(3): 271-374, August 2004
Abstract: There is significant progress in the observations, theory, and understanding of the x-ray and EUV emissions from comets since their discovery in 1996. That discovery was so puzzling because comets appear to be more efficient emitters of x-rays than the Moon by a factor of 80 000. The detected emissions are general properties of comets and have been currently detected and analyzed in thirteen comets from five orbiting observatories. The observational studies before 2000 were based on x-ray cameras and low resolution (E/deltaE ≈ 1.5-3) instruments and focused on the morphology of xrays, their correlations with gas and dust productions in comets and with the solar x-rays and the solar wind. Even those observations made it possible to choose uniquely charge exchange between the solar wind heavy ions and cometary neutrals as the main excitation process. The recently published spectra are of much better quality and result in the identification of the emissions of the multiply charged ions of O, C, Ne, Mg, and Si which are brought to comets by the solar wind. The observed spectra have been used to study the solar wind composition and its variations. Theoretical analyses of x-ray and EUV photon excitation in comets by charge exchange, scattering of the solar photons by attogram dust particles, energetic electron impact and bremsstrahlung, collisions between cometary and interplanetary dust, and solar x-ray scattering and fluorescence in comets have been made. These analyses confirm charge exchange as the main excitation mechanism, which is responsible for more than 90% of the observed emission, while each of the other processes is limited to a few percent or less. The theory of charge exchange and different methods of calculation for charge exchange are considered. Laboratory studies of charge exchange relevant to the conditions in comets are reviewed. Total and state-selective cross sections of charge exchange measured in the laboratory are tabulated. Simulations of synthetic spectra of charge exchange in comets are discussed. X-ray and EUV emissions from comets are related to different disciplines and fields such as cometary physics, fundamental physics, x-rays spectroscopy, and space physics.


There are a number of charge exchange reactions that inolve water, and result in X-ray emission, a fact which has indeed been long since proven & observed. An example from the paper:

O+7 + H2O -> O+6 + H2O+ + 727 eV

That 727 eV can come out as a single photon, or as a cascade of several photons. This has been observed at other comets before, and is confirmed by laboratory experiments.


What I would like to know is, how they determined what the status of the solar wind is at the location of Tempel 1?
We won't know for sure until they publish the real science, as opposed to the PR. But it's not very hard to do. The solar wind flow is predictable, it moves along the solar magnetic field. The solar wind speed & density are measured, as well as the magnetic field. All you need to do is measure the solar wind upstream from your point of interest, in this case the comet, with an appropriate time delay to compensate for the propagation speed. This is a fairly standard technique. It works.


... but I didn't see any plot with X-ray data ...
That's because you didn't follow the link from the Universe Today Story (http://www.universetoday.com/am/publish/250_000_water_tonnes.html) to the RAS News Release (http://www.ras.org.uk/index.php?option=com_content&task=view&id=979&Itemid=2) to the Images Page (http://www.star.le.ac.uk/~rw/deepimpact/), where the plots are located. Didn't anybody do that? It's right out there in plain sight?


On earth x ray are produced electrons hitting metal foil not steam.
On Earth, X-rays are produced by electrons hitting anything, including water, that produces bremsstrahlung (http://scienceworld.wolfram.com/physics/Bremsstrahlung.html). At a comet, you expect (and see) bremsstrahlung from electrons encountering the cometary bow shock. But keep in mind the charge exchange mechanism that I illustrated up the page. That kind of interaction between cometary water and heavy ions in the solar wind is responsible for a large chunk, if not most, of the X-ray emission following deep impact.


The surprising thing for me is the peak measurement was after five days had elapsed. Anyone got any ideas as to why this was?
The X-ray emission does not come from the impact, it comes from the interaction between the solar wind and material released by the impact. As the cloud of released material expands, more of it becomes acesssible to the solar wind for charge exchange & X-ray generation. But after 5 days, it must have become spread too thin, decreasing the probability of an encounter with solar wind ions, and so decreasing the X-ray emission. That's my guess, but it looks reasonable to me.


Adds a little more weight to EU model IMHO
Why? There is nothing happening here that is not well understood in terms of standard physics. In fact, if you look at the physics, you realize that what has been observed here is actually more damaging than friendly to any EU hypothesis. That's because the charge exchange reactions produce X-rays of characteristic energy, which identify the reaction just as any spectral feature identifies its maker. While the energy can come out in cascade, it can also come out as a single photon. So what we observe are X-ray line emission features which are unique to the specific reactions. That is not a prediction of any EU model. In fact, I don't see how any EU model could predict X-rays at all, because it can't account for the energy that generates the X-rays.

And that's why it's time to retreat to ATM.

Gerald Lukaniuk
2006-Apr-06, 08:16 PM
Essentiallly we only know that more xrays are hitting our instruments from that section of space than has been previously observed obviously attributed to the comet. The reflectivity of metals has been pinned down to electron clouds in the structures, I don't know about individual atoms. Confined ionized gases no doubt produced in earthly experiments become reflective as well fluorescent(ei gas or free electron laser,maser) as well. The co-olaborating evidence of energy production and (possibly x-ray flourescing) cloud are conspicuously absent implicating a change in reflectivity if it continues to be localized to the comet. It is unlikely ionized gas would not be confined on the surface Ps. Semiconductors produce x rays similar to metals and ofcourse are shiny.

Nereid
2006-Apr-06, 09:30 PM
First, a reminder to all folk who wish to post into this thread: per the BAUT rules, you may not make reference to ATM ideas here! This is direct contravention of the rules, and repeat violations will result in the suspension of your BAUT membership.

Second, if you do wish to present an ATM case, based on the results in the OP, there is at least one ATM thread that is entirely an appropriate place for you to do that.

Finally, if you have doubts as to the BAUT policy in this regard, please PM me (or ask in the About BAUT section).

ATKINS
2006-Apr-06, 10:13 PM
Surely it is now time to move the entire thread to the ATM section?
Too many dirty ATM words/arguments for chaste mainstream ears?

iantresman
2006-Apr-06, 10:28 PM
First, here is a nice, recent, 103 page review of the physics of X-ray and EUV emission from comets, which covers all of the known mechanisms. Unfortunately, the paper itself is not available online, only the abstract. So you have to go find Space Science Reviews the old fashioned way. But of course, anyone who is seriously interested will do that.

Any idea whether it mentions the production of x-rays from the acceleration of electrons through double layers, and their subsquent constriction as they enter a z-pinch (standard peer-reviewed plasma physics [ref] (http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=1988LaPaB...6..409B&db_key=AST&d ata_type=HTML&format=&high=42ca922c9c32480))?

Regards,
Ian Tresman

sol88
2006-Apr-07, 01:22 AM
Tim


These analyses confirm charge exchange as the main excitation mechanism, which is responsible for more than 90% of the observed emission, while each of the other processes is limited to a few percent or less.

How can there be a charge seperation/exchange in space??

Further:


There are a number of charge exchange reactions that inolve water, and result in X-ray emission, a fact which has indeed been long since proven & observed. An example from the paper:

O+7 + H2O -> O+6 + H2O+ + 727 eV

That 727 eV can come out as a single photon, or as a cascade of several photons. This has been observed at other comets before, and is confirmed by laboratory experiments.

So what kinda initial charge are we looking at to proform this proccess?


Nereid

First, a reminder to all folk who wish to post into this thread: per the BAUT rules, you may not make reference to ATM ideas here! This is direct contravention of the rules, and repeat violations will result in the suspension of your BAUT membership.

Second, if you do wish to present an ATM case, based on the results in the OP, there is at least one ATM thread that is entirely an appropriate place for you to do that.

Finally, if you have doubts as to the BAUT policy in this regard, please PM me (or ask in the About BAUT section).
then


ATKINS
Quote:
Originally Posted by Tim Thompson
Surely it is now time to move the entire thread to the ATM section?

Too many dirty ATM words/arguments for chaste mainstream ears?

ROLF :lol: :lol: :shifty:

Tim Thompson
2006-Apr-07, 03:04 AM
How can there be a charge seperation/exchange in space?? ... So what kinda initial charge are we looking at to proform this proccess?
Look at the equation: O+7 + H2O -> O+6 + H2O+ + 727 eV

The 7-times ionized oxygen atom has a strong enough net charge (+7), so that when it gets close enough to the neutral water molecule, it strips off an electron. So the H2O becomes H2O+, having lost one electron, and the O+7 becomes O+6, losing one unit of excess positive charge, since it has gained an electron. So, the charge exchange is the exchange of one electron between the oxygen atom and the water molecule. The X-ray energy comes from the de-excitation of the oxygen atom.

Tim Thompson
2006-Apr-07, 04:08 AM
Any idea whether it mentions the production of x-rays from the acceleration of electrons through double layers ...
See my response (http://www.bautforum.com/showpost.php?p=719805&postcount=2056) in the ATM EU thread (http://www.bautforum.com/showthread.php?t=28596&page=69). I put it there lest I offend the rules about ATM discussions here.

pfrenzel@mn.rr.com
2006-Apr-07, 10:42 AM
This may seem an inane and even obvious question to ask (to spout logic, the question wouldn't be obvious, it's the answer that would). Regardless:

Does the water/water vapor on Temple 1 consist of "heavy" water--HDO, not H2O?

In the not-so-distant past, during the hullabaloo regarding the comet dubbed "Linnear" (C/1999 S4), I first took note of this substance.

--Just wondering.

antoniseb
2006-Apr-07, 02:24 PM
Does the water/water vapor on Temple 1 consist of "heavy" water--HDO, not H2O?

There is no doubt that Tempel1 contains some HDO and some D2O, but it certainly is less abundant than H2O. It *is* an interesting question what is the isotope ratio compared to the Sun, the Earth, and other comets. Eventually, when we have a lot of datapoints, this will tell a side of the story of the creation of the Solar System.

edit: respelled "Tempel"

Gerald Lukaniuk
2006-Apr-07, 03:44 PM
Data from tempel shows xray out put from tempel returned to a higher but but still linear level. It doesn't say if the xray spectrum distribution has changed, but it already seems to be on a data curve that could be mixed and matched and blended with isotope and ionization ev's to fit any scenerio. The comet xeeemx to have moved far enough to imply it's a surface change. I'm liking the idea that conditions there have now allowed for plasmoid polaritons confined in metal debris or by products such as hydrides.

Jakenorrish
2006-Apr-12, 01:17 PM
That discovery was so puzzling because comets appear to be more efficient emitters of x-rays than the Moon by a factor of 80 000.

Hi Tim,

I'm well out of my depth here, that much is true, but the above sentence needs some clarification for a humble amateur who takes an interest in these things. Does this sentence mean that the comet emits 80 000 times as many x-rays per mass as the moon, or does it mean it emits the same quantity of x-rays but 80 000 times as many are detected?

Tim Thompson
2006-Apr-12, 02:22 PM
... Does this sentence mean that the comet emits 80,000 times as many x-rays per mass as the moon, or does it mean it emits the same quantity of x-rays but 80,000 times as many are detected?
First let me point out that the sentence comes from the abstract of the Krasnopolsky, Greenwood & Stancil review paper (http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=2004SSRv..113..271K&db_key=AST&d ata_type=HTML&format=&high=4366fa465131189), and is not directly attributable to me. As it turns out, the sentence means neither of the above.

It is interesting to compare the ratios of X-ray to visual luminosities for comet Hyakutake and the Moon. This was done using the visual magnitudes of Hyakutake and the Moon corrected for geocentric distances (Krasnopolsky, et al., 2000 (http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=2000Icar..146..152K&db_key=AST&d ata_type=HTML&format=&high=4366fa465113681)). In terms of these ratios the comet appeared to be a more efficient emitter of X-rays than the Moon by a factor of 8x104
Now you know as much as I do. I assume that the ratio of X-ray emission to visual emission for the comet is 80,000 times greater than is the same ratio for the moon, which makes sense. On page 276 the authors report that the actual X-ray emission from Hyakutake (http://cometography.com/lcomets/1996b2.html), as measured by ROSAT (http://heasarc.gsfc.nasa.gov/docs/rosat/), was 6000 times greater than the X-ray emission from the Moon, without any compensation for the fact that the Moon is much closer.

Jakenorrish
2006-Apr-13, 10:21 AM
Nice one Tim, thanks for the help.

trinitree88
2006-Apr-13, 11:46 AM
Layers only need to be atoms thin. Copper is extremely ductile,alloys can be formed that are even more so. Gold and silver are used also. An oz of gold makes sq miles of foil. Tumbling effects might account for variances. No jokes about pins though.

Nitpick. Re;An ounce of gold...square miles of foil.
A troy ounce of gold...~ 31.103 grams. Density of gold ~ 19.3 grams per cc. So the cube would be ~ 1.612 cc. For foil, height X area must equal same net volume.....1.612 ccs.....so the thickness of the foil determines the area. Gold beaters hammer it out to ~ 0.0001 mm, or 0.00001 cm. Dividing 1.612 cc by 0.00001 cm yields ~ 161,158 cm2. A square meter contains 10,000 cm2. So it's about 16.12 square meters, or a block of foil ~ 4 meters on an edge from the cube.
The square mile (singular, not miles)...is about ~ 160,711 times larger in surface area. My dad painted signs, handled gold leaf, covered the State House dome in Massachusetts.
http://www.iodata.com/news/culture.php?newsID=4&tot=74&ts=4&tsc=23

antoniseb
2006-Apr-13, 01:32 PM
I use gold leaf for my calligraphy, so I'm fairly familiar with its properties too. Gerald seems to be suggesting that somehow Copper can be turned in to a layer spread a few atoms thick across a large portion of the comet Tempel 1 in such a way as to be on the surface above the dust, and giving off the same spectrum of xrays as water being dissociated by Solar radiation.

It is good to see some outside the box thinking. What he's proposing doesn't add up.

Jerry
2006-Apr-17, 01:49 AM
First, a reminder to all folk who wish to post into this thread: per the BAUT rules, you may not make reference to ATM ideas here! This is direct contravention of the rules, and repeat violations will result in the suspension of your BAUT membership.

Second, if you do wish to present an ATM case, based on the results in the OP, there is at least one ATM thread that is entirely an appropriate place for you to do that.

Finally, if you have doubts as to the BAUT policy in this regard, please PM me (or ask in the About BAUT section).
It could be argued that this article is ATM: Every other report about the moisture content of Tempel 1 from many MS sources depicted a moisture release that was much less than expected. Here they have used an extrapolation technique that redraws the baseline and report much higher levels of H20. If I tried to do something like that to support an ATM idea, I would be laughed right off the board.

Where an iffy extrapolation comes up with numbers 2-3 orders of magnitude higher than conventional observation techniques - everyone should be very leary - even if the iffy part agrees with prior expectations. This is healthy skepticism.

sol88
2006-Apr-17, 01:41 PM
Jerry Jensen wrote:
It could be argued that this article is ATM: Every other report about the moisture content of Tempel 1 from many MS sources depicted a moisture release that was much less than expected. Here they have used an extrapolation technique that redraws the baseline and report much higher levels of H20. If I tried to do something like that to support an ATM idea, I would be laughed right off the board.

Where an iffy extrapolation comes up with numbers 2-3 orders of magnitude higher than conventional observation techniques - everyone should be very leary - even if the iffy part agrees with prior expectations.

Great point Jerry, after having a little forum tennis over in the ATM (http://www.bautforum.com/showthread.php?t=28596&page=67) section.

Seems at the moment this is the best tool to use, to quote you, healthy skepticism is good.