Dark or black meteors are, in
all probability, due to fatigue. When a meteoroid enters the atmosphere
the friction it encounters causes an ionized train that glows because the
ions are in a highly excited state. When they recombine with atomic nuclei
any excess energy is emitted as light. So dark meteors are not apparently
possible. As yet, no one has undertaken research to see when, in a meteor
watch, dark meteors begin to appear. In all probability, they will occur
towards the end of the watch when the observer is tired.
There are more believable reports
of dark meteors crossing the face of the Moon. The most notable case concerned
W.H.Steavenson in November 1920 who saw a dark meteor cross his telescope's
field of view while he was observing the lunar surface. He noted that the
meteor was in perfect focus.
It would be very easy to
dismiss Steavenson's observation were it not for the fact that he was one
of the most experienced observers of his day. He had received the Hannah
Jackson Medal from the Royal Astronomical Society in 1928, was Editor of
The
Observatory between 1929-33, and President of the RAS from 1957-59.
His view was that the object was a meteor but its contrast with the much
brighter lunar surface made it appear dark in much the same way the sunspots
appear dark against the more luminous sun.
Reports of both dark and
light meteors occurring during the day are not unknown though it seems
likely that such observations are due to flocks of birds, locust and seeds.
Copyright
1996 Philip M. Bagnall
Anomalous
Meteor Phenomena
Audible
Meteors and Fireballs
Curved,
Kinked, Spiral and Wavy Meteors
Nebulous
Meteors
Disk
and Point-Source Meteors
Multi-Tailed
Meteors
Long
Duration Trains
Reporting
AMP
Meteorite
Information
Meteorite
Links
Meteors
Home
Page