It's a warm, sunny day, and you try to place a cellular phone call, but there's more static on the phone than there is during a massive thunderstorm. It's inexplicable. Or is it?
Scientists from several institutes, including the National Center for Atmospheric Research and the National Science Foundation, were aboard a C-130 Hercules cargo jet in the Caribbean on Thursday, to observe the solar eclipse and discover whether cell phone and other communications snafus are related to solar disturbances.
The all-day mission, launched from Panama City, Panama, used new detection technology designed to test theories concerning "coronal mass ejections" - the sun's own form of eruptions - and develop better forecasting models for magnetic disturbances here on Earth. If successful, the forecasts could be used to help design technologies and strategies to prevent the solar magnetic disturbances from wreaking havoc with communications infrastructure and electric power grids.
The Western Hemisphere's last total eclipse of the century began Thursday at 10:56 a.m. EST and lasted about four minutes. It was visible only in the Galapagos, northern Venezuela and Colombia, Aruba, Curacao, Bonaire, Montserrat, Antigua and Guadeloupe. Totality means the moon blocks all but the sun's corona, or outer atmosphere of the sun, casting the earth into darkness through which the moon, stars and planets shine.
The corona is about a million times dimmer than the sun itself, said Clifford Jacobs, program officer at the NSF. Researchers observed the corona with a device called a coronagraph, an instrument that blacks out the disk. A new infrared camera, also deemed essential to the effort, made its debut on the cargo jet. The camera's infrared array detector was recently declassified by the government for peacetime use.
"It [the detector] will be used to detect the interplanetary dust particles, invisible to sensors so far," said Jacobs, in an interview before the launch. "The glare of the sun normally obscures such infrared emissions, so an eclipse is a rare opportunity to look for this dust with new technology."
Until now, no one has ever fully measured the power of the solar disturbances, and the eclipse provided a brief window of opportunity for modern scientists, said Jacobs. "You can only observe this particular type of radiation during an eclipse."
Coronal mass ejections, it is theorized, send radiation waves to the earth that interfere with and distort cellular and other communications operating in the radio spectrum.
The pilots guided the aircraft observatory to a height of 18,000 feet for a period of about 12 hours. The detectors were pointed directly at the sun through an open window in the plane, a somewhat risky operation for the sake of data collection. And since the craft's cabin cannot be pressurized, the five scientists and reserve crew on board all had to wear oxygen masks.
"This is an interesting situation," said Jacobs. "Since the spectral lines we want to observe are not well-transmitted by windows, a piece of glass may cut out the radiation. So basically, you have to fly the plane with an open port. The instrument looks up into the clear air. You also want to get as far above the moisture of the atmosphere as possible, because moisture tends to diminish that area of the spectrum."
NCAR solar physicist Philip Judge said the risk is worth it. "We won't really know what's going on in the corona until we can measure the magnetic field," he said. Scientists hope to discern the nature of the evolution of coronal fields during the solar cycle, as well as the causes of solar flares and the coronal mass ejections that cause disrupting "space weather," he added.
Long term, the mission could also lead to the creation of new technology. Detection of the magnetic field's signal could build the case for constructing a "coronal magnetograph," he said, which would be a more advanced version of the coronagraph that measures the magnetic properties of the corona.
