2000-04-09 - Oceanside, CA - Fireball

Bright fireball low in the southeast sky. Primarily white, although with a greenish tint.

I was driving south on interstate 5 about 5 or 10 miles south of Oceanside, CA. This is in north San Diego county. The highway heads generally south by southeast, not counting the curves, of course. I noticed a bright light source in the upper left corner of the windshield. I had emerged from a point along my line of sight where it was blocked by the roof of the car. In less than a second, it disappeared behind some high ground that was fairly near the highway. The light source had the appearance of a fireball; mostly white but with a greenish tint. It was about the size of the cross-section of a pencil held at arm's length, or about half the diameter of my smallest fingernail. It had a divided tail, more distinct along the top and bottom of the tail, and less distinct in the center. It was bright but not uncomfortable to look at, akin to looking at a bright streetlight. I can't give a very good account of my position, or its direction from me, or the angle above the horizontal when it disappeared; I was busy driving. I thought for a moment about what I had seen, then remembered to look at the clock. The clock read 1:11. I guessed that I had actually seen the fireball at 1:10. Here are some impressions (as opposed to observations). The fireball seemed to come roughly out of the northwest and to be heading roughly southeast. I had that impression that it was heading away from be at about a 45 degree aspect (as if I were going south and it was going southeast). I guessed that it was coming down at about a 45 degree angle, although the down angle looked more like 60 degrees because of the aspect angle (my impression of it). It did not look simply like a round light source; I could see irregularities. I could also see irregularities in the tail. From this, I think that it was close (whatever that means, in a relative sense, for fireballs). It looked so low to the ground and was moving so fast (about 10-15 degrees line of sight in less than a second) and coming down at such a steep angle that I was sure that it would hit the ground. I saw no evidence of any such hit (such as a brighter flash, for example). (note: using a fist at arm's length as 12 degrees) In thinking about the tail, it doesn't seem likely that the split appearance was due to any asymmetry in the object. That is certainly possible, of course. It seems more likely, though, for the tail to be eminating from the "limb" area that was closest to the undisturbed air. That is, for the tail to be coming off in a ring, forming a hollow cylinder behind the fireball. In looking roughly tangent to the cylinder (at the edge), the observer would be looking through more of the tail material than when looking at the middle. This would (I think) result in the effect that I saw.