Weird Astronomy by David A.J. Seargent

Author:David A.J. Seargent
Language: eng
Format: epub
Publisher: Springer New York, New York, NY

Black Meteors

Have you ever been watching the sky for meteors – probably ­during the time of a meteor shower – when you suddenly seem to see a dark object shoot across the sky for a short distance. What you see looks just like a small meteor, in all but one important respect. It is not luminous!

“Black meteor” reports are certainly not confined to novice meteor watchers. They are experienced by old hands at the art as well. The trouble is, according to all accepted wisdom, they simply cannot exist!

Any macroscopic physical object traveling at meteor speed through the atmosphere necessarily must become incandescent due to friction. There is simply no way around this. So if they don’t exist, why are they so often reported?

The usual explanation is that these events are optical illusions. In support of this, it is noted that many of the sightings occur either just after a meteor watch begins or shortly before one ends. In the first instance, it is asserted, the human eye has not properly settled down to dark adaptation, and misperceptions are more likely to happen.

Conversely, toward the end of the watch (especially if it has been a long one), fatigue is prone to start setting in. Under these circumstances, one is more likely to “see” something that isn’t really there.

On the other hand, sometimes a black meteor might indeed be a real object. The trouble is, it will not be a meteor!

If one is observing from a site that is free from low-level glare while at the same time having a mildly light polluted sky – a rural area close to a large town, for instance – a flying insect silhouetted against the background sky might be mistaken for a dark meteor. In this instance, however, the “track” is likely to be quite long.

If there is also a degree of local glare, as is common on a lighted suburban street, a flying insect has less chance of being seen in silhouette against the sky. Under these conditions, it is more likely to be illuminated from beneath by the local streetlights. Rather than being mistaken for a black meteor, it is then far more likely to be mistaken for an ordinary luminous meteor, as is evidenced by the earlier instance of a night bird being mistaken for an erratic Perseid!

Project 15Black and Erratic Meteors

Here is an interesting project for somebody with meteor-watching friends in both suburbia and the country. Simply have them record each instance of apparent black or curved meteors and compare the two sets of results. If bugs and birds are really responsible for these reports, the rural observers should report more black and fewer curved “meteors” than their suburban counterparts.

Does this happen? Only one way to find out!

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