'Space Bubbles' May Have Blacked Out Communications in Afghanastan During Fatal Battle

In the early morning hours of March 4, 2002, military officers in Afghanastan radioed a Chinook helicopter heading for the snowcapped peak of Takur Ghar; the peak was under enemy control. Unfortunately, the helicopter never got the message and just after daybreak, the helicopter crash-landed on the peak, killing three men.

Now, scientists have taken a closer look at why this message was never received. It turns out that it wasn't intentional or human error. Instead, the radio interference may be explained by plasma bubbles, which are essentially interruptions by space weather.

Giant plasma bubbles are wispy clouds of electrically charged gas particles. They form after dark in the upper atmosphere and are typically about 62 miles wide. These bubbles can be seen as they bend and disperse radio waves, interfering with communications. Sunlight usually keeps plasma stable during the day but at night, the charged particles recombine to form electrically neutral atoms and molecules again. Because the recombination happens more quickly at lower altitudes, bubbles rise up through the denser plasma above.

Peak bubble season in Afghanistan usually occurs in the spring. Yet in order to see whether plasma bubbles could be responsible for the interrupted communications during the battle of Takur Ghar, scientists took a closer look. They examined data from the Global Ultraviolet Imager (GUVI) instrument aboard NASA's TIMED mission, which studies the composition and dynamics of Earth's upper atmosphere.

In the end, they found that there was a plasma bubble directly between the helicopter and communications satellite during the time of the battle. While the bubble probably wasn't large enough to disturb radio communications by itself, it likely contributed to the interference caused by the complex terrain in the area; together, these factors essentially blacked out communications.

The findings actually may help researchers predict and minimize the effects of plasma bubbles in the future. The new model that they created, which combines data from several satellite-based systems, could be a huge asset to future operations.

The findings are published in the journal Space Weather.