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Re: APOD: Meteor Misses Galaxy (2019 Apr 30)
Posted: Mon Jun 03, 2019 12:32 pm
by Iksarfighter
Chris Peterson wrote: ↑Mon Jun 03, 2019 12:21 pm
Iksarfighter wrote: ↑Mon Jun 03, 2019 9:06 am
Chris Peterson wrote: ↑Fri May 03, 2019 4:26 am
It is, in fact, not something that can be reliably determined from the information contained in the image. It's unlikely the imager would be able to answer the question, unless he actually observed this, which I doubt. The color information is ambiguous, given the broadband filters and the fact that colors come both from meteoroid composition and atmospheric gases. The light curve isn't helpful, as meteors can brighten quickly and decay slowly, or brighten slowly and decay quickly. The shape of the train is potentially useful, but only if there is high altitude wind information available for very near the time of the image... also unlikely. An active meteor shower could be diagnostic, but for the last few months sporadics have been more numerous than any shower members.
So all in all, not much to go on.
Meteor is going left to right if I compare with auroras, red is high and green is lower altitude.
Am I right ?
It's not certain. Too many things can influence meteor color, especially in an image. It's not a bad assumption, but it's far from definitive.
So this assumption needs to be studied.
Re: APOD: Meteor Misses Galaxy (2019 Apr 30)
Posted: Mon Jun 03, 2019 12:34 pm
by Chris Peterson
Iksarfighter wrote: ↑Mon Jun 03, 2019 12:32 pm
Chris Peterson wrote: ↑Mon Jun 03, 2019 12:21 pm
Iksarfighter wrote: ↑Mon Jun 03, 2019 9:06 am
Meteor is going left to right if I compare with auroras, red is high and green is lower altitude.
Am I right ?
It's not certain. Too many things can influence meteor color, especially in an image. It's not a bad assumption, but it's far from definitive.
So this assumption needs to be studied.
No, that phenomenon is understood. But a meteor is not an aurora. The color of a meteor is determined by more than the species of atmospheric gases it is heating.
Re: APOD: Meteor Misses Galaxy (2019 Apr 30)
Posted: Mon Jun 03, 2019 2:25 pm
by Iksarfighter
Not only red and green but
the same red and
the same green and nothing out of these red and green.
A spectral analysis would have put me right.
Seems like this meteor is ionizing the same gases as solar wind does.
My bet it is going from left to right
Re: APOD: Meteor Misses Galaxy (2019 Apr 30)
Posted: Mon Jun 03, 2019 2:49 pm
by Chris Peterson
Iksarfighter wrote: ↑Mon Jun 03, 2019 2:25 pm
Not only red and green but
the same red and
the same green and nothing out of these red and green.
A spectral analysis would have put me right.
Seems like this meteor is ionizing the same gases as solar wind does.
My bet it is going from left to right :P
A spectral analysis would tell us. Not necessarily because of the red-green transition, though. The spectrum would show us the sequence that meteoritic materials were being ablated, starting with sodium and other volatiles, and ending with the refractory components. That would be definitive for the direction of travel.