for National Geographic News
Twin satellites are making possible the first 3-D pictures of solar storms, NASA announced today.
The new technology will allow for earlier warnings about solar storms that can disrupt GPS signals and power grids, damage satellites, and bombard astronauts with solar radiation, experts said.
The data for the 3-D models come from the Solar Terrestrial Relations Observatory (STEREO), a pair of spacecraft deployed in fall 2006. Not unlike human eyes, the satellites' two points of view allow for combination images that render scenes in three dimensions.
So far, the STEREO siblings have imaged solar storms, aka coronal mass ejections, aka CMEs. (See solar storm pictures from the STEREO craft.)
"Before this unique mission, measurements and the subsequent data of a CME observed near the sun had to wait until the ejections arrived at Earth, three to seven days later," said Angelos Vourlidas, a solar physicist at the Naval Research Laboratory in Washington and a STEREO project scientist, in a statement.
"Now we can see a CME from the time it leaves the solar surface until it reaches Earth, and we can reconstruct the event in 3-D directly from the images," added Vourlidas, who presented the new findings during a teleconference with other mission scientists. Their work will be published in an upcoming special issue of the journal Solar Physics.
Stalking Solar Storms
Solar storms are powerful, sudden eruptions of plasma and magnetic energy from the sun's outer atmosphere. (Related: "Space Weather Forecast: More Solar Storms on the Way.")
Older, Earth-based technology can't discern the speed of the blasts when they're headed for Earth. But STEREO can see the direction and speed of storms, including those headed for Earth, because of its dual vantage points.
The STEREO craft are also able to sample the contents and gauge the magnetic properties of solar eruptions, which provide major clues as to how the storms will interact with Earth's magnetic field.
It all adds up to more time for us Earthlings to react.
The new tech should alert us to adverse space weather a full 24 hours before it hits Earth—versus the current 12-hour advance notice—according to Michael Kaiser, a STEREO project scientist from NASA's Goddard Space Flight Center in Greenbelt, Maryland.
"Wussy Little CMEs"
Physicist Vic Pizzo said, "We always knew if you had two views, you could do a vastly better job" of predicting the effects of space weather.
"And that's what they're getting here," said Pizzo, who works with the National Oceanic and Atmospheric Administration's Space Weather Prediction Center in Boulder, Colorado, and was not involved with the new study.
And given that the sun is experiencing one of its quietest periods in decades, the best is yet to come, Pizzo said.
"Most of the things coming off are wussy little CMEs," he said. "A lot of the payoff is down the line."
STEREO's Vourlidas might agree.
"Now we can accomplish this," he said during the teleconference, "and we are ready for the next solar maximum."
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