I saw almost the exact same thing in the same part of the sky and around the same time of night taking my nightly walk about 6 weeks or so prior to this, but the color was white to red instead of blue.
Location
Address
Newton, MA
Latitude
42° 21' 25.81'' N (42.35717°)
Longitude
71° 11' 29.11'' W (-71.19142°)
Elevation
16.301521m
Time and Duration
Local Date & Time
2019-07-24 23:03 EDT
UT Date & Time
2019-07-25 03:03 UT
Duration
≈1.5s
Direction
Moving direction
From up left to down right
Descent Angle
105°
Moving
Facing azimuth
200°
First azimuth
160°
First elevation
25°
Last azimuth
240°
Last elevation
7°
Brightness and color
Stellar Magnitude
-
Color
Blue, Light Blue, Light Green
Concurrent Sound
Observation
No
Remarks
-
Delayed Sound
Observation
No
Remarks
-
Persistent train
Observation
Yes
Duration
2s
Length
30°
Remarks
flash left a green puff, then a trail of blue as it streaked across, widest at the front and narrowed nearest the initial flash
