 |
Science Frontiers ONLINE No. 130: JUL-AUG 2000 |
|
| 
|
Anomalous High Altitude Luminosity (AHAL)
Observational anomalies are abundant. Two Leonid fireballs were seen glowing at 160 kilometers by Japanese scientists. In 1998, a Dutch team in China detected bright Leonids at 200 kilometers! In addition, some Russian reentering space-craft began glowing well above 100 kilometers. ANAL is a solid phenomenon.
Of course, the density of the upper atmosphere does increase somewhat when solar activity is high. Atmospheric gravity waves can also cause the atmosphere to bulge out. But these effects are inadequate to explain all observations.
R. Spalding, at Sandia National Laboratories, ventures that ions in the upper atmosphere are electrostatically attracted to meteors and create light when they collide with them. A. Ol'khovatov suggests that "plasma instabilities" may be involved. To learn more about these, go to the latter's web site at:
(Ol'khovatov, Andrei; "Anomalous High Altitude Luminosity," Meteorite!, 6:18, May 2000.)
Comments. AHAL remains unexplained. Interestingly enough, ANAL occurs at the same high altitudes where some meteors are heard on the ground, even though the air at these altitudes is too thin to transmit sound! These anomalous hisses are termed "electrophonic sounds." See GSH2 in Earthquakes, Tides, etc.
Other Sites of Interest
|