Cape Canaveral (US): NASA is poised to send four identical spacecraft on a billion-dollar mission to study the explosive give-and-take of the Earth and sun's magnetic fields.
Liftoff of the unmanned rocket, and NASA's Magnetospheric Multiscale spacecraft, is set for today from Cape Canaveral, Florida. Forecasters put the odds of good weather at 70 per cent.
The spacecraft will be launched into an oblong orbit stretching thousands of miles into the magnetosphere. They will fly in pyramid formation to provide 3-D views of magnetic reconnection on the smallest of scales.
Magnetic reconnection is what happens when magnetic fields like those around Earth and the sun come together, break apart, then come together again, releasing vast energy. This repeated process drives the aurora, as well as potentially disruptive solar storms.