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dgavin
2005-Jul-04, 08:32 AM
They talked a bit about the spectal analysis of the ejecta and said the following.

"We're seeing some unidentifiable spectral signatures."

Wonder if maybe they found a new element by accident?

Jerry
2005-Jul-04, 09:34 AM
A lot of unexpected metal would produce a hot, messy spectrum. A denser than expected comet would cause a lot of Doppler blurring of the spectra. It will take some time to sort it all out.

Yorkshireman
2005-Jul-04, 10:04 AM
A lot of unexpected metal would produce a hot, messy spectrum. A denser than expected comet would cause a lot of Doppler blurring of the spectra. It will take some time to sort it all out.

Care to make an actual prediction of the types and quantities of heavy metals you expect to see in the spectral signature Jerrry?

R.A.F.
2005-Jul-04, 11:29 AM
A lot of unexpected metal would produce a hot, messy spectrum. A denser than expected comet would cause a lot of Doppler blurring of the spectra. It will take some time to sort it all out.

For cryin' out loud, Jerry, give it a rest!

Sticks
2005-Jul-04, 02:36 PM
According to the BBC News site (http://news.bbc.co.uk/1/hi/sci/tech/4647673.stm)



Professor Iwan Williams, from Queen Mary, University of London, who is working on Europe's Rosetta mission to a comet, was also taken aback by the scale of the event.

"It was like mosquito hitting a 747. What we've found is that the mosquito didn't splat on the surface, it's actually gone through the windscreen."


A Mosquito going through a windscreen would be serious :o

The plume that was given up, how long did it last and could it affect the trajectory of the commet. I seem to remember that one of the ideas put forward to deflect a comet was to heat oneside so it would make a jet and steer it away from Earth.

So has this plume the capability of steering this comet on a less than benign trajectory? :(

kucharek
2005-Jul-04, 02:39 PM
According to the BBC News site (http://news.bbc.co.uk/1/hi/sci/tech/4647673.stm)



Professor Iwan Williams, from Queen Mary, University of London, who is working on Europe's Rosetta mission to a comet, was also taken aback by the scale of the event.

"It was like mosquito hitting a 747. What we've found is that the mosquito didn't splat on the surface, it's actually gone through the windscreen."


A Mosquito going through a windscreen would be serious :o

The plume that was given up, how long did it last and could it affect the trajectory of the commet. I seem to remember that one of the ideas put forward to deflect a comet was to heat oneside so it would make a jet and steer it away from Earth.

So has this plume the capability of steering this comet on a less than benign trajectory? :(

Nope. All in all, the energy put into the jet was limited by the kinetic energy of the impactor, which is tiny compared with the comet's.
For a real deflection you would need a continous jet. Landing a reactor on a comet and feeding it with comet ice or something like that.

Harald

Sticks
2005-Jul-04, 03:25 PM
So I don't need to cancel my magazine subscriptions then :oops:

Kizarvexis
2005-Jul-04, 04:07 PM
I remember reading on one of the official Deep Impact sites (can't find it now in the pic fest :) ) that the comets trajectory was expected to be changed by 10 meters (33ft). In 2024 the comet will pass by Jupiter and have it's orbit changed by 34 million kilometers (21 million miles). So even if the impact was a 1000 times stronger than expected and changed the comets course by 10 km, it will be swamped by Jupiter's changes in 2024.

Kizarvexis

Edit: Found it! The Planetary Society - Deep Impact Mission Timeline (http://www.planetary.org/news/2005/di_timeline_0630.html). The mention of the Jupiter flyby of the comet is at the bottom of the page.

Bozola
2005-Jul-04, 05:54 PM
A lot of unexpected metal would produce a hot, messy spectrum. A denser than expected comet would cause a lot of Doppler blurring of the spectra. It will take some time to sort it all out.

What causes a messy spectrum is a very unpure sample. Most spectral libraries are based on pure compounds and the more crap you add, the more blurred and difficult interpretation becomes.

Secondly, the spacecraft carries an INFRARED spectrometer. IR Specs are usually used to identify organic compounds. While the state of the art has left me some years ago, I cannot ever remember an IR spectometer used to identify elemental metals. From what I remember, IR is looking for the stretching and bending vibrations of carbon, oxygen, nitrogen compounds. I will be so bold as to say the IR cannot be used to identify elemental metals (since I have retired from that industry, I can afford the luxury of error ;) ).

I think you confusing it with and atomic emission spectrophotometer, an altogether different beast.