Solar storms--billion-ton clouds of solar plasma launched by the same sun explosions that spark solar flares--can be dangerous because they can damage satellites, disrupt communications, and cause power grid failures on Earth, according to NASA. Because of this, scientists have been working to try to predict their occurrence and their behavior.
New image-processing techniques scientists are using on STEREO are allowing them to see how solar eruptions develop into space storms on Earth, providing better information for space weather models to improve storm forecasting, according to Lika Guhathakurta, STEREO program scientist at NASA headquarters in Washington.
Previously, STEREO could not clearly show an image of the structure of a solar storm as it traveled toward Earth. This meant forecasters had to estimate when storms arrived without knowing the details of how they might grow and the effect they might have, according to NASA.
New images from cameras on one of the spacecraft reveal detailed features of a large CME in late 2008 that was directed toward Earth. The images connect the original magnetized structure in the sun's corona to the anatomy of the storm as it hit the planet three days later.
The spacecraft's wide-angle cameras made the images possible by detecting ordinary sunlight scattered by free-floating electrons in plasma clouds, according to NASA. The clouds are bright and easy to see when they first leave the sun, but become more difficult to detect as they expand into the void.
"Separating these faint signals from the star field behind them proved especially challenging, but it paid off," said Craig DeForest, scientist at the Southwest Research Institute in Boulder, Colo.
Through these observations, NASA scientists not only can predict the arrival time of a CME on Earth, but also its mass, according to NASA. The brightness of the cloud enabled researchers to calculate the cloud's gas density throughout the structure and compare it to direct measurements by other NASA spacecraft.
In the future, scientists can use this same technique to determine whether the Earth will be hit by a small or large cloud, and where on the sun the material originated, according to NASA.
STEREO consists of two observatories that orbit the sun, one ahead of Earth and one behind. The observatories are a part of NASA's Solar Terrestrial Probes program, which seeks to understand the fundamental physical processes of the space environment.
In the new, all-digital issue of InformationWeek Government: As federal agencies close data centers, they must drive up utilization of their remaining systems. That requires a well-conceived virtualization strategy. Download the issue now. (Free registration required.)