Starship Asterisk*

Chris Peterson wrote: ↑Thu Feb 04, 2021 2:44 pm

Mike Attas wrote: ↑Thu Feb 04, 2021 2:25 pm
Thank you all for your comments and observations about the direction of the train (or is it trail?).

Both a trail and a train. The trail is the path we see from the glowing meteoroid. The train is its afterglow of ionized gases, as well as any visible dust. Because this is a long exposure, the trail and the train largely overlap, so we can't tell what's what, except for the stuff that's blown to the side.

https://www.etymonline.com/search?q=trail wrote:
trail (n.) early 14c., "trailing part of a robe, gown, etc.," from trail (v.). The meaning "track or smell left by a person or animal" is also from 1580s. Meaning "path or track worn in wilderness" is attested from 1807. Trail of Tears in reference to the U.S. government's brutally incompetent Cherokee removal of 1838-9 is attested by 1908.
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train (n.) early 14c., "a drawing out, delay;" late 14c., "trailing part of a skirt, gown, or cloak;" also "retinue, procession," from Old French train "tracks, path, trail (of a rome or gown); act of dragging," from trainer "to pull, drag, draw," from Vulgar Latin *traginare, extended from *tragere "to pull," back-formation from tractus, past participle of Latin trahere "to pull, draw". General sense of "series, progression, succession, continuous course" is from late 15c.

https://www.guinnessworldrecords.com/news/2017/12/worlds-longest-wedding-dress-train-could-almost-cover-mount-everest-506087 wrote:
<<The world’s Longest wedding dress train has been unveiled in Caudry, a French town famous for its production of lace, 11 years after the Guinness World Records title was first set there. The spectacular white gown has an 8,095.40 m train which is almost long enough to cover Mount Everest (8,848 m)! Construction company Dynamic Projects, with the help of 15 volunteers, spent two months stitching individual pieces of the train before sewing them all together to form a whole. The attempt took place at the annual French fundraising event, AMF Telethon, which raises money for non-profit organisations such as the French Muscular Dystrophy Association.>>

Mike Attas wrote: ↑Thu Feb 04, 2021 2:25 pm Thank you all for your comments and observations about the direction of the train (or is it trail?). I’m glad others found it an interesting question too.

FLPhotoCatcher wrote: ↑Thu Feb 04, 2021 5:56 am Did you all miss the reply from the photographer? He said that the meteor was going from right to left.

FKuszaj wrote: ↑Tue Feb 02, 2021 3:41 pm

Mike Attas wrote: ↑Tue Feb 02, 2021 2:17 pm I agree that the photo is magnificent. But I have a question. Was the meteor going left to right, or right to left? Is it possible to tell from the photo? From the trail colours?

in the photo, from right to left!

FKuszaj wrote: ↑Tue Feb 02, 2021 3:41 pm

Mike Attas wrote: ↑Tue Feb 02, 2021 2:17 pm I agree that the photo is magnificent. But I have a question. Was the meteor going left to right, or right to left? Is it possible to tell from the photo? From the trail colours?

in the photo, from right to left!

neufer wrote: ↑Wed Feb 03, 2021 3:01 am

Chris Peterson wrote: ↑Tue Feb 02, 2021 11:21 pm

neufer wrote: ↑Tue Feb 02, 2021 11:10 pm
The blown-out red color must be low density
two minute excited atomic oxygen red 630.0 nm emission:

You mean the persistent train? Maybe... although two minutes is a pretty short time for this amount of drift. I'd also consider that we're seeing a sodium emission, which is the most common thing in these trains, not very well color corrected (sodium trains are orange-yellow).

Solar spectrum with Fraunhofer lines as it appears visually.

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589 nm emission sodium D lines are strong precisely because they are short lived (at night: see below).
630.0 nm atomic oxygen emission are long lived because they are "forbidden."

Chris Peterson wrote: ↑Tue Feb 02, 2021 11:21 pm

neufer wrote: ↑Tue Feb 02, 2021 11:10 pm
The blown-out red color must be low density
two minute excited atomic oxygen red 630.0 nm emission:

You mean the persistent train? Maybe... although two minutes is a pretty short time for this amount of drift. I'd also consider that we're seeing a sodium emission, which is the most common thing in these trains, not very well color corrected (sodium trains are orange-yellow).

https://www.britannica.com/science/climate-meteorology/Winds-in-the-stratosphere-and-mesosphere wrote:
<<The winds in the stratosphere and mesosphere are usually estimated from temperature data collected by satellites. The winds at these high levels are assumed to be geostrophic. Overall, in the midlatitudes, they have a westerly component in the winter and an easterly component in the summer. The highest zonal winds are around 60–70 metres per second (3.6 to 4.2 kilometers per minute) at 65–70 km above Earth’s surface.>>

https://tigerprints.clemson.edu/cgi/viewcontent.cgi?article=1129 wrote:
MESOSPHERE AND LOWER THERMOSPHERE NEUTRAL WINDS
OBSERVATIONS USING ROCKET-RELEASED CHEMICAL TRAILS AT POKERFLAT, ALASKA

Tianyu Zhan, Clemson University.
Clemson UniversityTigerPrints : Dissertations 8-2007

INTRODUCTION1. The mesosphere and lower thermosphere at high latitudes is a region with strong coupling with both the middle and lower neutral atmosphere and the ionosphere and magne-tosphere. The momentum and energy sources come from the dissipation of tides, planetary waves and gravity waves propagating upward from the troposphere and stratosphere, and from the ion drag, Joule heating and particle heating. During disturbed conditions, such as substorm events, the enhanced ionization and strong electric fields will further induce stronger coupling and the accelerated neutral wind pattern at E region and lower F re-gion represents a complex interaction between the auroral forcing and the tidal forcing.Mikkelsen et al. [1987] and Larsen et al. [1989] showed large horizontal neutral winds with magnitudes of 100–150 metres per second (6 to 9 kilometers per minute) in the region of 100 to 120 km altitude, observed by the chemical tracers released by sounding rockets under quiet conditions on March 20, 1985,and March 21, 1987, from Søndre Strømfjod, Greenland. Even larger westward horizontal neutral winds were observed during February and March 1978 by rocket-released trimethylaluminum (TMA) at Poker Flat, Alaska [Mikkelsen et al., 1981].
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3.5 The idea of using a chemical tracer (sodium) released by sounding rockets at high altitudes to obtain neutral wind velocities was first proposed by Bates [1950]. Numerous experiments with sodium and other chemical tracer releases were carried out thereafter. Sodium, lithium and trimethyl aluminum (TMA) have been used extensively as chemical tracers during the past four decades, all working well in the altitude range be-tween approximately 80 and 180 km. Sodium trails are visible due to resonant scattering of sunlight at a wavelength of 5890 ̊A, but it is extinguished quickly after sunset [Bedinger et al., 1958]. Therefore, wind measurements using sodium tracer are limited to dawn or dusk when the tracer is illuminated at high altitudes and the ground site is located where it is dark enough to observe the trails. Lithium tracers are visible due to red resonant emissions and thus havethe same limitation as sodium [Larsen 2002]. The exceptionally bright resonant emissionproduced by lithium makes daytime neutral wind measurements possible however [Rees etal., 1972].>>

neufer wrote: ↑Tue Feb 02, 2021 11:10 pm

Chris Peterson wrote: ↑Tue Feb 02, 2021 8:40 pm
The problem is that we can't reliably relate the colors in the image to either elements in the meteoroid or the atmosphere, because it's a single streak with the wake and trail superimposed on the primary source. The colors are seriously distorted.

That said, now that I know it isn't a Quadrantid, I would lean towards right to left, since the sort of explosive fragmentation that produces a persistent train is likely to occur at or near the end of the path, which would suggest the meteor ends at the left edge.

Thank goodness it's not a Colorful Quadrantid
... that would be SO hard to say!

Amazing photo of the Quadrantid meteor shower… from space!

The blown-out red color must be low density two minute excited atomic oxygen red 630.0 nm emission:

Chris Peterson wrote: ↑Tue Feb 02, 2021 8:40 pm
The problem is that we can't reliably relate the colors in the image to either elements in the meteoroid or the atmosphere, because it's a single streak with the wake and trail superimposed on the primary source. The colors are seriously distorted.

That said, now that I know it isn't a Quadrantid, I would lean towards right to left, since the sort of explosive fragmentation that produces a persistent train is likely to occur at or near the end of the path, which would suggest the meteor ends at the left edge.

https://en.wikipedia.org/wiki/Aurora wrote:
<<At its highest altitudes, excited atomic oxygen emits at 630 nm (red); low concentration of atoms and lower sensitivity of eyes at this wavelength make this color visible only under more intense solar activity. The low number of oxygen atoms and their gradually diminishing concentration is responsible for the faint appearance of the top parts of the "curtains". Scarlet, crimson, and carmine are the most often-seen hues of red for the auroras.

Oxygen is unusual in terms of its return to ground state: it can take 0.7 seconds to emit the 557.7 nm green light and up to two minutes for the red 630.0 nm emission. Collisions with other atoms or molecules absorb the excitation energy and prevent emission, this process is called collisional quenching. Because the highest parts of the atmosphere contain a higher percentage of oxygen and lower particle densities, such collisions are rare enough to allow time for oxygen to emit red light. Collisions become more frequent progressing down into the atmosphere due to increasing density, so that red emissions do not have time to happen, and eventually, even green light emissions are prevented. This is why there is a color differential with altitude; at high altitudes oxygen red dominates, then oxygen green and nitrogen blue/purple/red, then finally nitrogen blue/purple/red when collisions prevent oxygen from emitting anything. Green is the most common color. Then comes pink, a mixture of light green and red, followed by pure red, then yellow (a mixture of red and green), and finally, pure blue.>>

De58te wrote: ↑Tue Feb 02, 2021 8:30 pm

Mike Attas wrote: ↑Tue Feb 02, 2021 2:17 pm I agree that the photo is magnificent. But I have a question. Was the meteor going left to right, or right to left? Is it possible to tell from the photo? From the trail colours?

I would imagine, although I didn't pay close attention in physics classes, that the meteor was moving left to right. My argument; That timewise, even though this happened in a split second, that the laws of physics would state that the close proximity nitrogen and oxygen gases would heat up first red, and then a split second later the turbulence of the speeding meteor would drive the red gases outward. Not the other way around. Also it makes sense that the green nickel being much harder metal than soft magnesium would take longer to vaporize. I would guess that the magnesium went up first, leaving the nickel on the right.

Mike Attas wrote: ↑Tue Feb 02, 2021 2:17 pm I agree that the photo is magnificent. But I have a question. Was the meteor going left to right, or right to left? Is it possible to tell from the photo? From the trail colours?

FKuszaj wrote: ↑Tue Feb 02, 2021 3:41 pm

Mike Attas wrote: ↑Tue Feb 02, 2021 2:17 pm I agree that the photo is magnificent. But I have a question. Was the meteor going left to right, or right to left? Is it possible to tell from the photo? From the trail colours?

in the photo, from right to left!

Mike Attas wrote: ↑Tue Feb 02, 2021 2:17 pm I agree that the photo is magnificent. But I have a question. Was the meteor going left to right, or right to left? Is it possible to tell from the photo? From the trail colours?

Ironwood wrote: ↑Tue Feb 02, 2021 10:38 am I love it when I can find something I recognize in the background stars. If you look closely you can see the beautiful Leo Triplet group of three galaxies just above center. They have been featured many times here at APOD, most recently April 18, 2019.

Mike Attas wrote: ↑Tue Feb 02, 2021 2:17 pm I agree that the photo is magnificent. But I have a question. Was the meteor going left to right, or right to left? Is it possible to tell from the photo? From the trail colours?

Mike Attas wrote: ↑Tue Feb 02, 2021 2:17 pm I agree that the photo is magnificent. But I have a question. Was the meteor going left to right, or right to left? Is it possible to tell from the photo? From the trail colours?

Ironwood wrote: ↑Tue Feb 02, 2021 10:38 am I love it when I can find something I recognize in the background stars. If you look closely you can see the beautiful Leo Triplet group of three galaxies just above center. They have been featured many times here at APOD, most recently April 18, 2019.

Ironwood wrote: ↑Tue Feb 02, 2021 10:38 am I love it when I can find something I recognize in the background stars. If you look closely you can see the beautiful Leo Triplet group of three galaxies just above center. They have been featured many times here at APOD, most recently April 18, 2019.