April 23, 2007 — NASA released the first three-dimensional images of the sun Monday, saying the photos taken from twin spacecraft may lead to better predictions of solar eruptions that can affect communications and power lines on Earth.
"The first reaction was 'Great, the instruments work,' but beyond that the first reaction was 'Wow!'" scientist Simon Plunkett said as he explained the images to a room full of journalists and scientists wearing 3D glasses.
The images from the STEREO spacecraft (for Solar Terrestrial Relations Observatory) are available on the Internet and at museums and science centers nationwide.
The twin spacecraft, launched in October, are orbiting the sun, one slightly ahead of the Earth and one behind. The separation, just like the distance between our two eyes, provides the depth perception that allows the 3D images to be obtained.
That depth perception is also particularly helpful for studying a type of solar eruption called a coronal mass ejection. Along with overloading power lines and disrupting satellite communications, the eruptions can endanger astronauts on spacewalks. Scientists would like to improve predictions of the arrival time from the current day or so to a few hours, said Russell Howard, principal investigator for the Naval Research Laboratory project.
STEREO program scientist Madhulika Guhathakurta said scientists have until now been "modeling in the dark" when it came to predicting solar storms. The twin spacecraft give researchers the vantage point to "provide the observations needed to validate the models."
The sun has been relatively quiet since the launch, so STEREO scientists have not predicted the arrival of any storms yet, Plunkett said.
The eruptions — also called solar flares — typically blow a billion tons of the sun's atmosphere into space at a speed of 1 million mph. Besides power and communications problems, the phenomenon is responsible for the northern lights, or aurora borealis, the luminous display of lights seen in the upper latitudes of the Northern Hemisphere.
Kaiser said scientists would like to be able to predict solar disturbances, just as meteorologists are able to predict hurricane formation.
"We'd like to do the same thing with solar storms," Kaiser said. "We aren't quite there yet."
