On the night of 24-25 November 2017, the UK experienced two significant fireball events, reported by 343 individuals, marking it the most reported fireball night for UKMON (United Kingdom Meteor Observation Network).
The Midnight Fireball (20171124_235955)
On 24 November 2017, at 23:59 UT, the first fireball of the night was recorded by UKMON network cameras. The event was so bright that the cameras at Wilcot SW station (Richard Fleet) and Church Crookham station (Peter Campbell-Burns) were over-saturated with light. Due to this over-saturation, manual astrometry was performed on the sequence segments, omitting the saturated frames. The event was documented in video clips from both stations.
Key Details:
- Time: 23:59 UT
- Locations: Wilcot SW and Church Crookham
- Brightness: Over-saturated recordings, necessitating manual analysis
- Visual Observations: 113 reports, including fragmentation and sound effects
- Brightness Range: -10mag to -20mag
Path Calculation:
- Start Coordinates: N50.430099° W2.136627° over the English Channel
- End Coordinates: N50.812645° W1.914062° near Ferndown, GB
- Altitude: From 86.6 km to 25.9 km
- Velocity: Geocentric velocity of 15.58 km/s
Orbital Elements:
- Semi-major axis (a): 2.198 AU
- Perihelion (q): 0.7721 AU
- Eccentricity (e): 0.649
- Inclination (i): 3.02°
- Argument of perihelion (ω): 63.49°
- Longitude of ascending node (Ω): 62.6643°
The Morning Fireball (20171125_071306)
On 25 November 2017, at 07:13 UT, the second fireball was recorded by the Wilcot SW station camera and two dashboard cameras—one on the M4 highway near Port Talbot (Mark Lemon) and the other on the M5 highway near Churchdown (Craig Low). The astrometry of this event was conducted using the UFO Analyzer program and manual calculations.
Key Details:
- Time: 07:13 UT
- Locations: Wilcot SW, M4 near Port Talbot, M5 near Churchdown
- Brightness: Analysis required due to varied recording quality
- Visual Observations: 224 reports, including fragmentation and sound effects
- Brightness Range: -10mag to -20mag
Path Calculation:
- Start Coordinates: N49.971264° W1.899078° over the English Channel
- End Coordinates: N49.68513° W3.486542° over the English Channel
- Altitude: From 82.0 km to 38.8 km
- Velocity: Geocentric velocity of 20.42 km/s
Orbital Elements:
- Semi-major axis (a): 3.866 AU
- Perihelion (q): 0.8534 AU
- Eccentricity (e): 0.779
- Inclination (i): 22.68°
- Argument of perihelion (ω): 133.71°
- Longitude of ascending node (Ω): 242.9665°
Visual Observations
Visual observations for both fireballs were extensive, with reports submitted to the IMO database. Observers reported fragmentation and sound effects, contributing valuable data for the analysis.
Midnight Fireball:
- Observers: 113 from Great Britain and France
- Fragmentation Reports: 35
- Sound Effects: 4 during flight, 9 after flyover
Morning Fireball:
- Observers: 224 from Great Britain, Ireland, and France
- Fragmentation Reports: 105
- Sound Effects: 4 after flyout
Fireball 20171124_235955 (SPO)
The analysis showed the fireball’s path and meteoroid’s orbit, indicating an asteroidal origin.
Path and Orbit:
- Start Coordinates: N50.430099° W2.136627°
- End Coordinates: N50.812645° W1.914062°
- Velocity: 15.58 km/s
- Orbital Elements: a = 2.198 AU, q = 0.7721 AU, e = 0.649, i = 3.02°, ω = 63.49°, Ω = 62.6643°
Fireball 20171125_071306 (SPO)
The analysis indicated a cometary origin for this fireball.
Path and Orbit:
- Start Coordinates: N49.971264° W1.899078°
- End Coordinates: N49.68513° W3.486542°
- Velocity: 20.42 km/s
- Orbital Elements: a = 3.866 AU, q = 0.8534 AU, e = 0.779, i = 22.68°, ω = 133.71°, Ω = 242.9665°
The bright fireballs on the night of November 24-25, 2017, were significant astronomical events. The midnight fireball likely resulted from an asteroid, while the morning fireball had a cometary origin. These events provided valuable data for future studies and demonstrated the effectiveness of UKMON’s observation network.
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