Fwd: [UASR]> Parallel double meteor trails
[U A S R]> UFOs-, ALIENs-, SPACE- RESEARCH MAILING LIST <[U A S R]
Forwarding permission was given by William R. Corliss.
Science Frontiers, No. 153, May-Jun, 2004, pp. 1 & 2
< http://www.science-frontiers.com >
Parallel double meteor trails
Meteor-watchers, of which there are quite a few, report fairly often
observations of doubled meteor trails shining bright in the night sky.
Like aircraft contrails, these neatly parallel streaks are eventually
twisted and contorted by the winds of the upper atmosphere. The
Leonids are famous for producing a loose tapestry of bright trails
containing a few doublets.
Astronomers doubt that the pairs of parallel trails are traced out by
split meteors plunging side-by-side through the increasingly dense air.
If meteor break-up were the cause, they would also expect to see a few
triple or even higher-order parallel trails. They don't
The preferred explanation of double trails assumes that a single meteor
leaves a hollow tube of glowing debris. A "limb effect" makes the tube's
edges brighter than its center.
In *Geophysical Research Letters*, M.C. Kelley et al assert that the
brightness contrast between the edges of the putative tube and its center
is too great for the limb-effect explanation. Their solution:
...one train is due to excited gas from the meteor and the other,
lying below the first, comes from dust sedimenting under gravity.
(Ball, Philip; "Parallel Lines," *Nature*, 426:784, 2003)
Comment. If the components of the twin trails have different physical
causes, wouldn't the parallelism disappear more quickly than is observed---
especially in long sinuous double trails? In other words, the upper gas
trail would be affected very differently than the lower dust trail---and
[Science Frontiers is a bimonthly collection of digests of scientific
anomalies in the current literature. Published by the Sourcebook Project,
P.O. Box 107, Glen Arm, MD 21057. Annual subscription: $8.00.]