High-altitude metallic clouds, known as sporadic E layers, are formed by the vaporized remains of meteors burning up in the ionosphere. These layers, which hover approximately 60 miles above Earth, act as unpredictable mirrors for radio frequencies. By reflecting signals back toward the ground, they can disrupt long-distance communications, create false radar targets, and introduce errors into GPS technology.
Historically, researchers could only study these layers using sounding rockets that followed a single, narrow flight path. This limited perspective made it difficult to understand the full scope of the phenomenon. To address this, the SpEED Demon (Sporadic E Electrodynamics Demonstration) mission launched from NASA’s Wallops Flight Facility in Virginia on August 24, 2022. The mission utilized a new technique, deploying four ejectable probes alongside the main rocket payload to collect data from five distinct points simultaneously.
The findings, published in the Journal of Geophysical Research: Space Physics, indicate that sporadic E layers are not uniform, flat sheets of metallic particles. Instead, the data revealed a highly structured environment shaped by atmospheric turbulence and neutral winds. Lead author Henry Valentine, a researcher at the U.S. Naval Research Laboratory, noted that the layer appeared more like a "cinnamon roll" than a smooth pancake, with evidence suggesting that Kelvin-Helmholtz billows—a type of breaking-wave pattern—may influence its shape.
Principal investigator Aroh Barjatya of Embry-Riddle Aeronautical University described the transition from single-point measurements to multi-point sensing as moving from viewing a scene through a "crack in a wall" to looking through a "picket fence." This successful demonstration of multi-probe technology has since been applied to subsequent missions, including studies of solar eclipses and further investigations into sporadic E layers at different latitudes.
Source: NASA
暂无评论。快来发表第一条评论吧。