Starship Asterisk*

Chris Peterson wrote:

thomastank68 wrote:The correct term for this phenomena is a "Sprite" (or "Lightning Sprites").

Will APOD correct all references to Lighting Jets?

This is not a sprite. It is some kind of jet. "Lightning" might reasonably be replaced with "TLE", but "sprite" would be wrong.

Guest wrote:

geckzilla wrote:

madtom1999 wrote:Is the dotted streak (bottom left by the cloud top) a satellite or a spinning perseid?

Just an airplane.

Hum, if that is an airplane then how fast do you think it must be going, considering this is a single frame.

We are talking the streak just above the camera on the left side of the frame.

neufer wrote:

Ann wrote:
I'd love to know what causes the colors.

This jet lightning is purple to violet near bottom and red at top. Could this be related to blue jets and red sprites, in that the blue jets are lower than the red sprites? Could both these phenomena (or related ones) be seen at different levels of one huge jet?

I'm guessing that:

• blue jets are from ionized nitrogen atoms that regain an electron after being ionized;
  
  while red sprites are from ionized nitrogen atoms that return to their ground state.
  
  Purple to violet gigantic jets are a combination (and/or) ARGON.

https://en.wikipedia.org/wiki/Aurora wrote:
<<Auroras result from emissions of photons in the Earth's upper atmosphere, above 80 km, from ionized nitrogen atoms regaining an electron, and oxygen atoms and nitrogen based molecules returning from an excited state to ground state. They are ionized or excited by the collision of particles precipitated into the atmosphere. Both incoming electrons and protons may be involved. Excitation energy is lost within the atmosphere by the emission of a photon, or by collision with another atom or molecule:

oxygen emissions

• green or orange-red (630.0 nm), depending on the amount of energy absorbed.

nitrogen emissions

• blue: if the atom regains an electron after it has been ionized,
  red: if returning to ground state from an excited state.

Oxygen is unusual in terms of its return to ground state: it can take three quarters of a second to emit green light and up to two minutes to emit red. Collisions with other atoms or molecules absorb the excitation energy and prevent emission. Because the highest atmosphere has a higher percentage of oxygen and is sparsely distributed such collisions are rare enough to allow time for oxygen to emit red. Collisions become more frequent progressing down into the atmosphere, 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/red, then finally nitrogen blue/red when collisions prevent oxygen from emitting anything.>>

Ann wrote:

neufer wrote:

Ann wrote:
I'd love to know what causes the colors.

This jet lightning is purple to violet near bottom and red at top. Could this be related to blue jets and red sprites, in that the blue jets are lower than the red sprites? Could both these phenomena (or related ones) be seen at different levels of one huge jet?

I'm guessing that:

• blue jets are from ionized nitrogen atoms that regain an electron after being ionized;
  
  while red sprites are from ionized nitrogen atoms that return to their ground state.
  
  Purple to violet gigantic jets are a combination (and/or) ARGON.

https://en.wikipedia.org/wiki/Aurora wrote:
<<Auroras result from emissions of photons in the Earth's upper atmosphere, above 80 km, from ionized nitrogen atoms regaining an electron, and oxygen atoms and nitrogen based molecules returning from an excited state to ground state. They are ionized or excited by the collision of particles precipitated into the atmosphere. Both incoming electrons and protons may be involved. Excitation energy is lost within the atmosphere by the emission of a photon, or by collision with another atom or molecule:

oxygen emissions

• green or orange-red (630.0 nm), depending on the amount of energy absorbed.

nitrogen emissions

• blue: if the atom regains an electron after it has been ionized,
  red: if returning to ground state from an excited state.

Oxygen is unusual in terms of its return to ground state: it can take three quarters of a second to emit green light and up to two minutes to emit red. Collisions with other atoms or molecules absorb the excitation energy and prevent emission. Because the highest atmosphere has a higher percentage of oxygen and is sparsely distributed such collisions are rare enough to allow time for oxygen to emit red. Collisions become more frequent progressing down into the atmosphere, 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/red, then finally nitrogen blue/red when collisions prevent oxygen from emitting anything.>>

Thanks, Art, but I'm still confused. What sort of nitrogen emits blue light?

Ann wrote:
Interesting, Art....But like you said, does the onslaught of meteorites on the atmosphere cause (or aid) the appearance of TLE jets? Or do people simply notice and photograph the TLE jets during the Perseid showers, because so many people are watching, photographing and filming the night sky during that time?

(But aren't TLE jets seen during other meteor storms? If so, why not?)

BMAONE23 wrote:In other words..
Correlation but not causation?

Chris Peterson wrote:

BMAONE23 wrote:
In other words..
Correlation but not causation?

Not even that given how easily this could just be observational bias. That is, the correlation may be purely observational and not actual.

It seems unlikely that meteors could be a factor, given that they burn up much higher than the cloud tops where jets appear to originate.

neufer wrote:

Chris Peterson wrote:

BMAONE23 wrote:
In other words..
Correlation but not causation?

Not even that given how easily this could just be observational bias. That is, the correlation may be purely observational and not actual.

It seems unlikely that meteors could be a factor, given that they burn up much higher than the cloud tops where jets appear to originate.

They could provide a conducting layer at the level where jets appear to end.

Chris Peterson wrote:

neufer wrote:

Chris Peterson wrote:
It seems unlikely that meteors could be a factor, given that they burn up much higher than the cloud tops where jets appear to originate.

They could provide a conducting layer at the level where jets appear to end.

I don't think there's any evidence that meteors produce conducting layers. Their own path is briefly ionized, but we don't see things like differences in radio propagation during meteor showers (except for brief reflections off those ionized trails).

neufer wrote:

Chris Peterson wrote:

neufer wrote: They could provide a conducting layer at the level where jets appear to end.

I don't think there's any evidence that meteors produce conducting layers. Their own path is briefly ionized, but we don't see things like differences in radio propagation during meteor showers (except for brief reflections off those ionized trails).

Temporary ionized tendrils leading up to the ionosphere :?:

P.S., I think that it is all observational bias too but it is fun to speculate.