Reports Report 1144j (Event 1144-2018)

This report has been linked to the following event: Event 1144-2018
Observer
NameVadim N
Experience Level4/5
RemarksI did not see the actual fireball. I was walking and looking in the direction away from it. I was wearing headphones and listening to the music. Also, behind me was small hill which hid the horizon in the direction of the flash. Instantly the sky and surroundings became almost as bright as in daylight for a few seconds. The light was strange greenish in color. Only about a minute after the flash did I realize that it was and noted the time on the watch. It was 4:22 local (MST).I looked at the sky trying to find the trace, but did not find it. I took off the headphones and continued to walk. Then I heard the low frequency sound of a far away blast and noted the time again. It was 4:25. I estimate the delay between the flash and the sound at about 4 minutes, which gives a distance of about 72 kilometers. The direction has been approximated from the direction of my shadow produced by the light. From this it seems that the 'epicenter' of the event was near Fort Collins, CO. I checked the watch against time.gov when I got back and it is about 20-25 seconds ahead.
Location
AddressLongmont, CO
Latitude40° 5' 29.03'' N (40.09°)
Longitude 105° 9' 0.23'' W (-105.15°)
Elevation1630.96m
Time and Duration
Local Date & Time2018-03-24 04:21 MDT
UT Date & Time2018-03-24 10:21 UT
Duration≈1.5s
Direction
Moving directionFrom up right to down left
Descent Angle183°
Moving
Facing azimuth180°
First azimuth359.05°
First elevation
Last azimuth-
Last elevation
Brightness and color
Stellar Magnitude-20
ColorLight Green
Concurrent Sound
ObservationUnknown
Remarks-
Delayed Sound
ObservationYes
RemarksLow frequency sound of far away blast approximately 4 minutes after the flash.
Persistent train
ObservationNo
Duration-
Length-
Remarks-
Terminal flash
ObservationUnknown
Remarks-
Fragmentation
ObservationUnknown
Remarks-