A pair of spacecraft NASA plans to launch on August 31 will take stereoscopic pictures of the sun to give the first-ever three-dimensional views of its massive, weather-disrupting eruptions, US scientists have said.
The twin spacecraft, each the size of a small car, will join the Earth in its orbit, one moving ahead of the planet and one trailing, in the $478 million project.
By simultaneously measuring and recording solar flares and coronal mass ejections - huge eruptions that blast solar plasma into space - the two craft will give a "unique and revolutionary view" of the flow of energy between the sun and Earth.
It will also cut by half the time it takes, currently about 12 hours, to get warnings of geomagnetic storms headed toward the Earth that were produced by the eruptions, Michael Kaiser, project scientist for NASA's Solar Terrestrial Relations Observatory, said on Wednesday.
Such storms can wreck satellites and cause power and telecommunications outages on Earth. They can also endanger astronauts on journeys beyond the Earth's magnetic field.
"In terms of space-weather forecasting, we're where weather forecasters were in the 1950s," Kaiser said.
"They didn't see hurricanes until the rain clouds were right above them. In our case, we can see storms leaving the sun, but we have to make guesses and use models to figure out if and when they will impact Earth.