Fireball Path

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With respect to the fireball detailed in on the pictures page we can make some rough estimates of the meteor's size and location. 

By performing a great circle calculation and using the co-ordinates of the following points; the radiant, the start of the meteor and the end of the meteor we can estimate the angles involved. All angles are referred to the plane defined by the meteors path and the observer. I calculate that the meteor becomes visible at a point 50º from the radiant and is approximately 25º long. Based on these figures the geometry of the meteor path is as shown in Figure 1. The meteor is travelling on a path parallel to a line between the observer and the radiant. Initially the path of the meteor intersects the observers line-of-sight at an angle of 50º.

The meteor became visible 45º above the observer's horizon. And if we assume that the meteor first became visible at a height of 100 km, then we can calculate the distance from the observer (O) as follows:

 

 Given the length of OA and two angles we can solve the triangle OAB. This gives a meteor trail length of 62 km and a terminal distance of approximately 112 km from the observer.

 

Figure 1

The fireball finished close to α Draconis at an altitude of 39º above the horizon. Given the 112km distance from the observer, we can calculate the height above ground.

 

When we consider the plan view, the meteor became visible on a bearing of 56º east of true north. Given the 141km straight line distance to this point calculated previously and the 45º altitude of this point, then the horizontal distance is given by:

   

 The meteor burnt out on a bearing of 31º east of true north. Given the 112km straight line distance to this point calculated previously and the 39º altitude of this point, then the horizontal distance is given by:

Based on the above, the drawing below shows a plan of the meteors path. North is up.

 The map below shows an estimate of the meteor's path.