Re: [meteorite-list] Different colors of meteors/shooting stars
Hi Chris and List, It's also worth noting that cameras have some of the same constraints that the human eye does. Certain wavelengths of light are represented differently using various types of lenses and chips - the same is true for old 35mm film cameras and the most modern digital models. So, one can draw general visual conclusions about the colors of a fireball/bolide, but unless one is using the proper scientific equipment, your eye or consumer camera may alter what you are seeing in ways that make it difficult to make definitive judgements like that. Best regards and clear skies, MikeG -- - Web - http://www.galactic-stone.com Facebook - http://www.facebook.com/galacticstone Twitter - http://twitter.com/galacticstone Pinterest - http://pinterest.com/galacticstone - On 9/10/13, Chris Peterson wrote: > There may be some atmospheric effects, but I don't think they are the > usual explanation for the different colors people report. > > Color vision is highly variable from person to person. The same color > may be reported as pink, blue, or green by different people. This is > especially true when dealing with point sources, or with transient > effects. People are not good at judging the color of flashes. Some > people see a lot of color in stars, others will call you crazy if you > tell them that stars even have colors. > > After white, green is the most commonly reported color for meteors. As > Marco pointed out, that is typically from atmospheric oxygen. But it is > worth remembering that green also marks the peak of human color > sensitivity, and even if fairly strong wavelengths outside the green > region are present, the event may only be bright enough to stimulate our > green receptors. This is an effect visual astronomers are well aware of: > when you look at something like the Orion Nebula, most people see gray. > A few, with good vision, will see faint green. That's an oxygen > emission, which is much fainter that the dominant red hydrogen emission, > but that one simply doesn't stimulate our red sensors enough to show > color. So we see a "red" nebula as "green". > > Chris > > *** > Chris L Peterson > Cloudbait Observatory > http://www.cloudbait.com > > On 9/10/2013 12:51 PM, Doug Ross wrote: >> Thank you for the explanation, Chris. I have often wondered about this, >> since various colors often seem to be reported by different witnesses to >> the same meteor event. Wouldn't atmospheric filtering also affect the >> perceived color, depending on the angle and distance from which a meteor >> is viewed? In much the same way as the sun's color appears to change at >> sunset or sunrise. >> >> Doug Ross >> d...@dougross.net > > __ > > Visit the Archives at http://www.meteorite-list-archives.com > Meteorite-list mailing list > Meteorite-list@meteoritecentral.com > http://six.pairlist.net/mailman/listinfo/meteorite-list > __ Visit the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] Different colors of meteors/shooting stars
Thank you for the explanation, Chris. I have often wondered about this, since
various colors often seem to be reported by different witnesses to the same
meteor event. Wouldn't atmospheric filtering also affect the perceived color,
depending on the angle and distance from which a meteor is viewed? In much the
same way as the sun's color appears to change at sunset or sunrise.
Doug Ross
d...@dougross.net
> Hi Jim-
>
> As a rule, you can't tell much about a meteor's composition from the
> visual colors observed. The eye is a lousy spectrometer!
>
> The optical output of a meteor consists of hundreds of component
> emission lines, possibly a blackbody component in some cases, and some
> strong atmospheric emission lines. The visual effect is something close
> to white, sometimes with a color cast provided mainly by atmospheric
> ionization. While there are a handful of strong emission lines commonly
> observed in spectra, these are very narrow and therefore represent only
> a small part of the total luminous energy, which means they don't have
> much effect on the color ("color" being a physiological phenomenon, not
> a physical one).
>
> This isn't to say there might not be some cases where meteoroid
> composition is reflected in the color, but you can't make any
> generalizations.
>
> Chris
>
> ***
> Chris L Peterson
> Cloudbait Observatory
> http://www.cloudbait.com
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Re: [meteorite-list] Different colors of meteors/shooting stars
There may be some atmospheric effects, but I don't think they are the usual explanation for the different colors people report. Color vision is highly variable from person to person. The same color may be reported as pink, blue, or green by different people. This is especially true when dealing with point sources, or with transient effects. People are not good at judging the color of flashes. Some people see a lot of color in stars, others will call you crazy if you tell them that stars even have colors. After white, green is the most commonly reported color for meteors. As Marco pointed out, that is typically from atmospheric oxygen. But it is worth remembering that green also marks the peak of human color sensitivity, and even if fairly strong wavelengths outside the green region are present, the event may only be bright enough to stimulate our green receptors. This is an effect visual astronomers are well aware of: when you look at something like the Orion Nebula, most people see gray. A few, with good vision, will see faint green. That's an oxygen emission, which is much fainter that the dominant red hydrogen emission, but that one simply doesn't stimulate our red sensors enough to show color. So we see a "red" nebula as "green". Chris *** Chris L Peterson Cloudbait Observatory http://www.cloudbait.com On 9/10/2013 12:51 PM, Doug Ross wrote: Thank you for the explanation, Chris. I have often wondered about this, since various colors often seem to be reported by different witnesses to the same meteor event. Wouldn't atmospheric filtering also affect the perceived color, depending on the angle and distance from which a meteor is viewed? In much the same way as the sun's color appears to change at sunset or sunrise. Doug Ross d...@dougross.net __ Visit the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] Different colors of meteors/shooting stars
In addition to what Chris Peterson wrote: Colours perceived in meteors are quite often a result of the composition of the atmosphere at the altitude of the meteor, rather than the meteoroid composition. Take green colours sometimes reported for meteors. Almost invariably, someone will argue that it points to a metallic composition. In reality, the green is almost invariably the result of Oxygen in the atmosphere (the same origin as the green colour in Aurora). - Marco - Dr Marco (asteroid 183294) Langbroek Dutch Meteor Society (DMS) e-mail: d...@marcolangbroek.nl http://www.dmsweb.org http://www.marcolangbroek.nl - __ Visit the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] Different colors of meteors/shooting stars
Hi Jim-
As a rule, you can't tell much about a meteor's composition from the
visual colors observed. The eye is a lousy spectrometer!
The optical output of a meteor consists of hundreds of component
emission lines, possibly a blackbody component in some cases, and some
strong atmospheric emission lines. The visual effect is something close
to white, sometimes with a color cast provided mainly by atmospheric
ionization. While there are a handful of strong emission lines commonly
observed in spectra, these are very narrow and therefore represent only
a small part of the total luminous energy, which means they don't have
much effect on the color ("color" being a physiological phenomenon, not
a physical one).
This isn't to say there might not be some cases where meteoroid
composition is reflected in the color, but you can't make any
generalizations.
Chris
***
Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com
On 9/9/2013 10:38 PM, James Masny wrote:
Good evening list. Sorry if this has been discussed before, but are
different colors of meteors streaking through the atmosphere
indicative of certain minerals burning up? And what color represents
what minerals? I remember the 2001 Leonids, and seeing so many
different colors - pink, blue, white, yellow, green, orange. The
other night, I was outside, and I caught 2 fireballs, 1 changed color
from yellow to red, another from white to yellow.
All the best
Jim
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Re: [meteorite-list] Different colors of meteors/shooting stars
Also the following Borovicka's paper may be useful for this problem-solving: http://adsabs.harvard.edu/abs/1994A%26AS..103...83B Katsu OHTSUKA Tokyo, JAPAN > -Original Message- > From: Michael Mulgrew > Sent: Tue, Sep 10 2013 17:19:20 JST > To: Meteorite List > Subject: Re: [meteorite-list] Different colors of meteors/shooting stars > > Perhaps this link is more relevant: > http://laserstars.org/data/elements/ (please correct me if I'm wrong). > > Michael in so. Cal. > > On Mon, Sep 9, 2013 at 11:38 PM, Michael Mulgrew wrote: > > It was graciously pointed out to me that I erred and linked color > > spectra as produced by oxidation rather than by ionization, so feel > > free to disregard my link as it relates to meteors. > > > > > > "My bad", > > Michael in so. Cal. > > > > > >>> > >>> From: Michael Mulgrew > >>> To: James Masny > >>> Cc: Meteorite List > >>> Sent: Monday, September 9, 2013 9:50 PM > >>> Subject: Re: [meteorite-list] Different colors of meteors/shooting stars > >>> > >>> Jim, > >>> > >>> This link should provide some additional info: > >>> http://webmineral.com/help/FlameTest.shtml > >>> > >>> > >>> Happy gazing, > >>> Michael in so. Cal. > >>> > >>> On Mon, Sep 9, 2013 at 9:38 PM, James Masny wrote: > >>> > Good evening list. Sorry if this has been discussed before, but are > >>> > different colors of meteors streaking through the atmosphere > >>> > indicative of certain minerals burning up? And what color represents > >>> > what minerals? I remember the 2001 Leonids, and seeing so many > >>> > different colors - pink, blue, white, yellow, green, orange. The > >>> > other night, I was outside, and I caught 2 fireballs, 1 changed color > >>> > from yellow to red, another from white to yellow. > >>> > > >>> > All the best > >>> > Jim > >>> > __ > >>> > > >>> > Visit the Archives at http://www.meteorite-list-archives.com > >>> > Meteorite-list mailing list > >>> > Meteorite-list@meteoritecentral.com > >>> > http://six.pairlist.net/mailman/listinfo/meteorite-list > >>> __ > >>> > >>> Visit the Archives at http://www.meteorite-list-archives.com > >>> Meteorite-list mailing list > >>> Meteorite-list@meteoritecentral.com > >>> http://six.pairlist.net/mailman/listinfo/meteorite-list > >>> > >>> > >> > __ > > Visit the Archives at http://www.meteorite-list-archives.com > Meteorite-list mailing list > Meteorite-list@meteoritecentral.com > http://six.pairlist.net/mailman/listinfo/meteorite-list __ Visit the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] Different colors of meteors/shooting stars
Perhaps this link is more relevant: http://laserstars.org/data/elements/ (please correct me if I'm wrong). Michael in so. Cal. On Mon, Sep 9, 2013 at 11:38 PM, Michael Mulgrew wrote: > It was graciously pointed out to me that I erred and linked color > spectra as produced by oxidation rather than by ionization, so feel > free to disregard my link as it relates to meteors. > > > "My bad", > Michael in so. Cal. > > >>> >>> From: Michael Mulgrew >>> To: James Masny >>> Cc: Meteorite List >>> Sent: Monday, September 9, 2013 9:50 PM >>> Subject: Re: [meteorite-list] Different colors of meteors/shooting stars >>> >>> Jim, >>> >>> This link should provide some additional info: >>> http://webmineral.com/help/FlameTest.shtml >>> >>> >>> Happy gazing, >>> Michael in so. Cal. >>> >>> On Mon, Sep 9, 2013 at 9:38 PM, James Masny wrote: >>> > Good evening list. Sorry if this has been discussed before, but are >>> > different colors of meteors streaking through the atmosphere >>> > indicative of certain minerals burning up? And what color represents >>> > what minerals? I remember the 2001 Leonids, and seeing so many >>> > different colors - pink, blue, white, yellow, green, orange. The >>> > other night, I was outside, and I caught 2 fireballs, 1 changed color >>> > from yellow to red, another from white to yellow. >>> > >>> > All the best >>> > Jim >>> > __ >>> > >>> > Visit the Archives at http://www.meteorite-list-archives.com >>> > Meteorite-list mailing list >>> > Meteorite-list@meteoritecentral.com >>> > http://six.pairlist.net/mailman/listinfo/meteorite-list >>> __ >>> >>> Visit the Archives at http://www.meteorite-list-archives.com >>> Meteorite-list mailing list >>> Meteorite-list@meteoritecentral.com >>> http://six.pairlist.net/mailman/listinfo/meteorite-list >>> >>> >> __ Visit the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] Different colors of meteors/shooting stars
It was graciously pointed out to me that I erred and linked color spectra as produced by oxidation rather than by ionization, so feel free to disregard my link as it relates to meteors. "My bad", Michael in so. Cal. >> >> From: Michael Mulgrew >> To: James Masny >> Cc: Meteorite List >> Sent: Monday, September 9, 2013 9:50 PM >> Subject: Re: [meteorite-list] Different colors of meteors/shooting stars >> >> Jim, >> >> This link should provide some additional info: >> http://webmineral.com/help/FlameTest.shtml >> >> >> Happy gazing, >> Michael in so. Cal. >> >> On Mon, Sep 9, 2013 at 9:38 PM, James Masny wrote: >> > Good evening list. Sorry if this has been discussed before, but are >> > different colors of meteors streaking through the atmosphere >> > indicative of certain minerals burning up? And what color represents >> > what minerals? I remember the 2001 Leonids, and seeing so many >> > different colors - pink, blue, white, yellow, green, orange. The >> > other night, I was outside, and I caught 2 fireballs, 1 changed color >> > from yellow to red, another from white to yellow. >> > >> > All the best >> > Jim >> > __ >> > >> > Visit the Archives at http://www.meteorite-list-archives.com >> > Meteorite-list mailing list >> > Meteorite-list@meteoritecentral.com >> > http://six.pairlist.net/mailman/listinfo/meteorite-list >> __ >> >> Visit the Archives at http://www.meteorite-list-archives.com >> Meteorite-list mailing list >> Meteorite-list@meteoritecentral.com >> http://six.pairlist.net/mailman/listinfo/meteorite-list >> >> > __ Visit the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] Different colors of meteors/shooting stars
Jim, This link should provide some additional info: http://webmineral.com/help/FlameTest.shtml Happy gazing, Michael in so. Cal. On Mon, Sep 9, 2013 at 9:38 PM, James Masny wrote: > Good evening list. Sorry if this has been discussed before, but are > different colors of meteors streaking through the atmosphere > indicative of certain minerals burning up? And what color represents > what minerals? I remember the 2001 Leonids, and seeing so many > different colors - pink, blue, white, yellow, green, orange. The > other night, I was outside, and I caught 2 fireballs, 1 changed color > from yellow to red, another from white to yellow. > > All the best > Jim > __ > > Visit the Archives at http://www.meteorite-list-archives.com > Meteorite-list mailing list > Meteorite-list@meteoritecentral.com > http://six.pairlist.net/mailman/listinfo/meteorite-list __ Visit the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] Different colors of meteors/shooting stars
Good evening list. Sorry if this has been discussed before, but are different colors of meteors streaking through the atmosphere indicative of certain minerals burning up? And what color represents what minerals? I remember the 2001 Leonids, and seeing so many different colors - pink, blue, white, yellow, green, orange. The other night, I was outside, and I caught 2 fireballs, 1 changed color from yellow to red, another from white to yellow. All the best Jim __ Visit the Archives at http://www.meteorite-list-archives.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
