A car with friends of ours travelling on same highway and was about 20 minutes ahead of us reported seeing something similar but with more tail. It was beautiful! Additionally, I may not have shown my visual direction on your chart very accurately considering I was a passenger in a car as I observed this.
Location
Address
Edgemont, SD
Latitude
43° 17' 10.98'' N (43.286383°)
Longitude
104° 1' 16.67'' W (-104.021298°)
Elevation
1194.936m
Time and Duration
Local Date & Time
2015-10-11 19:15 MST
UT Date & Time
2015-10-12 01:15 UT
Duration
≈7.5s
Direction
Moving direction
From up left to down right
Descent Angle
167°
Moving
Facing azimuth
172.48°
First azimuth
179.03°
First elevation
31°
Last azimuth
196.61°
Last elevation
24°
Brightness and color
Stellar Magnitude
-6
Color
Green
Concurrent Sound
Observation
Unknown
Remarks
-
Delayed Sound
Observation
Unknown
Remarks
-
Persistent train
Observation
Yes
Duration
2s
Length
8°
Remarks
It also appeared green, but was too short to be sure it was even there. I was in a car and saw it long enough to have my sister look at it also but then it was gone
