A Plane Flying Across the Face of the Sun, with Contrails [Virgin Flight 353]

Mick West

Administrator
Staff member
DSCN5041-aw.jpg

This was a very lucky shot. I did not know the plane was there and it was only in front of the sun for about six seconds. Note also the two sunspots above and below the trail.

Nikon P900 @ 2000mm
Date Time Original: May 19, 2017, 7:47:19 PM (PDT, so 02:47AM May 20th UTC)
Approximate photo location: 38.63°, -121°

It presents an interesting geolocation opportunity for identifying the plane, due to the precisely known location the the sun at any time.
 

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Mick West

Administrator
Staff member
We can use SunCalc to see what direction the plane would be in at that precise time.
http://suncalc.net/#/38.63,-121,8/2017.05.19/19:47
20170520-084921-9wbpn.jpg

Then overlay this on a FlightRadar24 playback to see what planes are in that direction.
https://www.flightradar24.com/2017-05-20/02:47/12x/VRD353/d71c242
20170520-085241-etzjg.jpg

Overlaid:
20170520-085315-uepfz.jpg

It looks like the Virgin Plane is the best bet. Its tricky though, as there's three planes heading south (VX353 @36,750 descending, UA5523 @33,700 descending, and UA1170 @29,700 descending). And playback is inconsistent in positioning them. The above playback is labeled 02:47, but if I do it again at 02:48 I get the planes earlier in their tracks.

20170520-085829-6t4ap.jpg
 
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Mick West

Administrator
Staff member
Closeups of the plane, which appeared in two shots four seconds apart

7:47:15
20170520-090400-1m2yb.jpg


7:47:19
20170520-090441-1pf56.jpg

Both images overlaid. Handheld, so the sun is in different position and I've lined them up. Not sure how much the sun moves in 4 seconds
Both Overlay.jpg
 

Trailspotter

Senior Member.
ts tricky though, as there's three planes heading south (VX353 @36,750 descending, UA5523 @33,700 descending, and UA1170 @29,700 descending). And playback is inconsistent in positioning them. The above playback is labeled 02:47, but if I do it again at 02:48 I get the planes earlier in their tracks.
You can download the KML tracks of these planes and play them on Google Earth to see which one goes across the Sun if seen from the camera location.
 

Mick West

Administrator
Staff member
Can we ID the plane from the profile? All three planes are pretty similar. But I'd go for the A320 (Virgin) based on this:
20170520-093204-wxrej.jpg
 

Trailspotter

Senior Member.
Can we ID the plane from the profile? All three planes are pretty similar.
These airframes are of different lengths. Can you derive the length of the plane with a sufficient accuracy from its angular dimensions and the known distances to each plane?
 

Mick West

Administrator
Staff member
You can download the KML tracks of these planes and play them on Google Earth to see which one goes across the Sun if seen from the camera location.

Winner! Only the Virgin plane goes across the sun.
20170520-094659-qcupm.jpg

20170520-094744-t6ope.jpg

Viewed from my precise location (atmosphere turned off, to make the sun glare less)
ScreenFlow.gif
 
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Mick West

Administrator
Staff member
These airframes are of different lengths. Can you derive the length of the plane with a sufficient accuracy from its angular dimensions and the known distances to each plane?

Approximately, for full zoom it's
Size = distance * 0.01737 * pixels / image width
(See: https://www.metabunk.org/calculatin...in-a-p900-photo-when-distance-is-known.t8146/ )
20170520-102127-pfynh.jpg
Using the distance to the Virgin track
467,000 feet * 0.01737 * 63 / 4608 = 111 feet.

A320 = 122 feet
ERJ-175 = 104 feet
757-200 = 155 feet

So you could eliminate the 757
 
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