Spring Break
Probes capture 3-D images of solar explosions
Issue date: 4/30/09
The STEREO probes are a pair of spacecraft placed at different vantage points, one ahead of the Earth in its orbit around the sun and the other lagging behind. These two different vantage points are what allow for the 3-D images to be generated, much like how having our eyes in slightly different positions on our faces gives us the ability to perceive depth.
However, the probes have to be aligned just right to make sure the data is consistent over time. "APL spacecraft experts are helping STEREO scientists reconstruct 3-D imagery, collected by the spacecraft, by very accurately pointing the spacecraft and reducing its jitter or movement," Marren said. From the reconstructed images, scientists can track a CME's shape, velocity, mass and trajectory from when it leaves the surface of the sun to when it reaches Earth.
Knowing these factors improves our ability to forecast when a CME arrives, but not what it will do. For that, the contents of the CME need to be known. The effects of solar storms depend on how much plasma they contain and on the strength and orientation of their magnetic fields, not only on their shape. For that, new satellites will be needed, ranging from new space-based observatories to probes that would approach the sun's surface and actually enter emerging CMEs.
Nevertheless, STEREO still has a role to play. Its probes will continue to track the sun on opposite sides, and may even directly encounter CMEs, allowing scientists to observe a solar storm as it travels through space.
"We plan to analyze a number of CMEs that are directed to Earth or one of the STEREO spacecraft and quantify the improvement in predicting when the CME will impact [Earth or STEREO] by using our 3-D information," Vourlidas said.
However, the probes have to be aligned just right to make sure the data is consistent over time. "APL spacecraft experts are helping STEREO scientists reconstruct 3-D imagery, collected by the spacecraft, by very accurately pointing the spacecraft and reducing its jitter or movement," Marren said. From the reconstructed images, scientists can track a CME's shape, velocity, mass and trajectory from when it leaves the surface of the sun to when it reaches Earth.
Knowing these factors improves our ability to forecast when a CME arrives, but not what it will do. For that, the contents of the CME need to be known. The effects of solar storms depend on how much plasma they contain and on the strength and orientation of their magnetic fields, not only on their shape. For that, new satellites will be needed, ranging from new space-based observatories to probes that would approach the sun's surface and actually enter emerging CMEs.
Nevertheless, STEREO still has a role to play. Its probes will continue to track the sun on opposite sides, and may even directly encounter CMEs, allowing scientists to observe a solar storm as it travels through space.
"We plan to analyze a number of CMEs that are directed to Earth or one of the STEREO spacecraft and quantify the improvement in predicting when the CME will impact [Earth or STEREO] by using our 3-D information," Vourlidas said.
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