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Fraser
2008-Dec-04, 06:10 AM
Things appeared to get a little strange in the field of X-ray astronomy when the NASA/ESA ROSAT observatory started seeing emissions from a series of comets. This discovery in 1996 was a conundrum; how could X-rays, more commonly associated with hot plasmas, be produced by some of the coldest bodies in the Solar System? In [...]

More... (http://www.universetoday.com/2008/12/03/swift-detects-x-ray-emissions-from-comets/)

Swift
2008-Dec-04, 02:22 PM
I did no such thing!

;)

01101001
2008-Dec-04, 05:29 PM
I did no such thing!

Thank you, Swift.

Jerry
2008-Dec-04, 07:07 PM
This is highly irritating. Alternative theorists have been saying for at least this long that the explosive emissions from the backside of comets must be electrical in nature, not due directly to solar heating. I think this has been confirmed in the emissivity data from the Deep Impact mission.


The total power output from the coma can top a billion Watts.

Arcing and sparking. If this kind of energy is being released, it also means the path of the comet is being altered, and since the energy is released as the comet moves into the the inner solar system, there are good reasons to assume the path of comets, and presumably everything else, become less elliptical at much greater rates than purely Newtonian mechanal models predict. Extrapolating to other, larger bodies: We don't need massive collisions or accruing dust to build major planetary systems! If an earth-sized body came winging into the solar system from 'out there' what kind of Xray display would we see? Is this how mysterious gamma rays are produced?

Anyone who has watched time lapse of SOHO data can observe how marvelous displays of the solar flares seem to coordinate with cometary approaches to the sun. I have always (almost) written this off as coincidental, because it seems too simple to connect-the-dots (and therefore since only ATMer's make this claim, it is unlikely meaningful). Why it is so inconcievable, knowing that these massive electrical currents pop and crackle about comets in their solar approach; that a complimentary event could be occurring near the surface of the sun?

Something is major-league missing from our modern conceptions of planetary physics.

trinitree88
2008-Dec-08, 05:15 PM
Not too, too surprising. The one that really surprised me was the x-rays coming from peeling Scotch tape in a vacuum. pete:think:


see:http://blogs.discovermagazine.com/80beats/2008/10/22/peeling-scotch-tape-powers-x-ray-machine/

Jerry
2008-Dec-08, 09:54 PM
It's charge exchange!! read about in the other electric comet threads, it's been gone over to death!

I'm sick of these EU'rs coming in here with there crackpot ideas and spoiling our big bang fun :evil:

Any other threads going on this topic at the moment?


“You wouldn’t have thought that so much of the mechanical energy would come out as X-rays,” says Ken Suslick, an expert in mechanoluminescence…. “The adhesive on the tape is an amorphous liquid, not crystalline. What’s causing the transfer of charge, of electrons or protons, what the accepting and donor groups are — these things are much less clear”
I ask again, is anyone extrapolating this to a planetary scale?


And it must have been a very big surprise for researchers who assumed ROSAT could only be used to glimpse the transient flash of a GRB or supernova, possibly spawning the birth of black holes. Comets simply did not feature in the design of this mission.

However, since the launch of another GRB hunter in 2005, NASA's Swift Gamma-ray Explorer has spotted 380 GRBs, 80 supernovae and… 6 comets. So how can a comet possibly be studied by equipment intended for something so radically different?
Because the interaction between a comet and the sun is radically different from pre-orbital science explanations?

trinitree88
2008-Dec-09, 02:11 PM
I ask again, is anyone extrapolating this to a planetary scale?


Because the interaction between a comet and the sun is radically different from pre-orbital science explanations?


Jerry. The interaction of the solar wind, impacting the cometary tail, would contain high velocity electrons striking a target,....the standard method of generating X-rays. A maxwellian distribution of velocities would give a spread of the spectra. Not too implausible for a Satellite designed to detect high energy photons to pick up a comet near the sun, or within the heliosphere.
pete

see:http://en.wikipedia.org/wiki/X-ray_machine

and...SWIFT is designed to measure gamma, hard X-ray, and UV photons...see:http://heasarc.gsfc.nasa.gov/docs/swift/about_swift/factsheet.pdf

see also XMM EPIC CCD specs:http://www.swift.psu.edu/xrt/fpca.html...hard x-ray

Jerry
2008-Dec-10, 01:36 AM
Jerry. The interaction of the solar wind, impacting the cometary tail, would contain high velocity electrons striking a target,....the standard method of generating X-rays. A maxwellian distribution of velocities would give a spread of the spectra. Not too implausible for a Satellite designed to detect high energy photons to pick up a comet near the sun, or within the heliosphere.

Not too implausible? Why wasn't it expected? We have known about the solar wind for decades; known that it carries charges. By 1996, we had probes measuring the ionic strength well beyond 3AU, and we had visited comets. If anyone would have predicted gega Watts of Xray's would be generated when solar winds interact with comets in say,1986, this type of prediction would have been scoffed at - just as even the suggestion that solar wind particles colliding near the helopause could contributed to the microwave background is ridiculed today.

Unknown at this time, is the mechanism that allows lightning to generate gamma rays (a cosmic ray precursor has been excluded.) As I mentioned before, we know many of the gaseous jets that form the tails of comets are emitted from the dark side. We also know that the thermal density of comets is very low, that is, most of the heat absorbed on the sun-facing side is immediately re-emitted - there is not enough energy absorbed to result in jetting.

If you follow the articles about Enceladus, general reaction has run the gamit from 'this is unbelievable' to 'these events are thought to be tidal' even though tidal explanations come up short in many, many ways. Nobody knows what's going on.

JustAFriend
2008-Dec-10, 02:06 PM
Hmmmm.... lets see.... you've got an object moving millions of miles an hour slamming through the solar system impacting on all the dust, debris, gas and particles in it's way... is anyone really surprised they're making x-rays????

Jerry
2008-Dec-10, 07:15 PM
Hmmmm.... lets see.... you've got an object moving millions of miles an hour slamming through the solar system impacting on all the dust, debris, gas and particles in it's way... is anyone really surprised they're making x-rays????
Find one single prediction ATM/Mainstream, or even science fiction that interactions between comets and the solar wind would result in Xrays. If you try to do the calculations, you run into a couple of problems: The cometary mass is not charged, or rather not expected to be charged/and or develop significant charge as particles leave the body. (Yes I know this is not true, but that is observational, not a prediction). Another problem is that when collisions occur, even if one small particle from the solar wind is charged, most of the energy should be absorbed as heat energy by the cometary particle,which is many times more massive than your average solar wind particle. Xrays generally require both high potentials and significant magnetic fields; altering the course of the charged particle and inducing an Xray. A simple collision results in a significant thermal rise, but not significant Xrays. Observable Xrays require high current levels as well. Where are the necessary currents and magnetic fields coming from?

Buttercup
2008-Dec-10, 07:27 PM
Um...I just think it's neat. :D {{dons lead apron}}