the 'green impact? flash' and the black shape seen in the center of the fireball were firsts for me
Location
Address
East Dubuque, IA
Latitude
42° 28' 4.3'' N (42.467862°)
Longitude
90° 36' 20.63'' W (-90.60573°)
Elevation
187.203m
Time and Duration
Local Date & Time
2017-12-18 23:52 CST
UT Date & Time
2017-12-19 05:52 UT
Duration
≈3.5s
Direction
Moving direction
From down left to up right
Descent Angle
22°
Moving
Facing azimuth
98.04°
First azimuth
99°
First elevation
70°
Last azimuth
95°
Last elevation
-
Brightness and color
Stellar Magnitude
-6
Color
lt yellow to yellowish to orangish yellow to lt green to green from start to end
Concurrent Sound
Observation
Unknown
Remarks
-
Delayed Sound
Observation
No
Remarks
-
Persistent train
Observation
No
Duration
-
Length
-
Remarks
-
Terminal flash
Observation
Yes
Remarks
a beat after i saw it disappear behind the hill i saw a half spherical shaped green flash brighter at the center horizon area fading out to the top and sides.
Fragmentation
Observation
Yes
Remarks
the head of the fireball was very elongated and the last few split seconds before it went behind the horizon noticed dark spot/specks at the center of the fireball bottom head portion.