neufer wrote: ↑Wed Dec 29, 2021 4:18 pm
johnnydeep wrote: ↑Wed Dec 29, 2021 12:46 pm
alter-ego wrote: ↑Wed Dec 29, 2021 4:46 am
Pon - Thank you very much for the time and care you've spent following the posts, clarifying and correcting our understanding of your images, and sharing your many years of experience recording and figuring out the plume(s). For us, one APOD sometimes does not tell enough information, and for several of us, we want to make sense what's going on. Consequently, we sometimes don't understand and make wrong assumptions. It is rare that an APOD contributor dives in like you have here. It's been a breath of fresh air. Your patience, helpful nature and detailed presentation have removed all questions about your image being "fake". For me, this APOD has set a new bar that I'd like to see more often.
Thanks again and keep up the great work!
Amen to that! And for the record, I, for one, never thought the shot was faked, only that it needed further explanation of it's unusual appearance. Unusual to me anyway - my posting history will show that I find a lot of stuff unusual looking
Until someone addresses my concern about an Ariane rocket
that stopped firing over East Africa
at an altitude of 1,000 km being clearly visible in the skies over Thailand I remain a skeptic.
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Sounds like you don't question the visibility anymore. I'm posting this anyway for those curious.
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The fact the image was taken 10 min later is the deal maker. Unfortunately, lacking the tracking data during this 10-minute interval, I had to make assumptions that I wasn't all that happy with.
>> Independently calculated the Alt/Az and nadir Lat/Long of the JWST/plume location assuming the plume(s) tracked with it, and
>> Compared these results with Stellarium's Alt/Az of the imaged plume(s)
>> Results:
- Calculated [Alt, Az] @ 12:57 UT =
[23°,232°] Note: Plume trajectory looks reasonable,but appears to lag JWST location (make sense).
- Stellarium [Alt, Az] @ 12:57 UT =
[17°,237°]
- Estimated NASA Tracking Altitude (km) @ 12:57 UT = 4792 km
- Estimated NASA Tracking Distance from East African coast @ 12:57 UT = 3508 km
- Google Map great circle distance from East African coast @ 12:57 UT ≈ 3525 km
→ Google Map shows plume nadir [Long, Lat] ≈ [4°S, 71°E]
>> Details:
• Critical JWST data source:
https://www.youtube.com/watch?v=7nT7JGZMbtM
- At elapsed times 24.0, 25.0, 26.0 and 27.0 minutes I used the tracking parameters from the first panel to calculate the plume location
and altitude (km)
- I used the 3rd panel (map) to replicate the projected ground track into Google Maps between Africa's East coast and the plume location
• I used Google maps to:
- Set up the great circle arcs that connect the following two locations to the final calculated plume location (projected onto Earth) @ 12:57 UT
The locations are the African East coast location @ 12:47 UT and Pon's location at Chiang Mai, Thailand
- Determine the predicted plume azimuth wrt Pon, and
- Iteratively solve for the plume-image altitude (degrees) by adjusting arc lengths / angles until the predictions
were consistent with tracking data.
• As mentioned, Stellarium provided the imaged plume alt/az
•
Assumptions
- Plume(s) followed the same trajectory Altitude (km) and Distance (km) tracks as JWST
- Tracking data is very accurate.
→ Estimated corrections for velocity and position changes by calculating best-fit quadratic equations for both distance and altitude (km)
>> Solving for plume visibility at 12:57 UT:
- Solution independent of image alt/az.
- One solution for a fixed altitude (km) above Earths surface.
- Predicted altitude (degrees) is higher, and azimuth is further east. Suggests the plume(s) lag JWST.
- Additional calculations assuming a constant average velocity (linear best fits, not quadratic) predict plume(s) are further lagging the JWST.
Pretty convincing I'd say.