Predicting "Space Weather" -New Insights from the Hinode Solar-Optical Telescope

Solar flares, massive energetic explosions that rise up from the Sun, can damage man-made satellites and pose a radiation hazard to astronauts. Despite decades of study, many aspects of this phenomenon are little understood.

Scientists do not know how big solar flares can get because we have only been tracking them since the beginning of the Space Age. A typical solar flare releases the energy equivalent to a billion hydrogen bombs and spew into space a hundred billion tons or so of deadly high-energy particles. Our magnetosphere and atmosphere block them like a giant sunscreen or divert them safely toward the poles where they produce our auroras.

The Hinode Solar Optical Telescope observations are now shedding light on activities that accelerate solar particles in flares. Hinode is a Japanese led international mission in co-operation with NASA, the European Space Agency, and the Norwegian Space Center.

Louise Harra at the Mullard Space Science Laboratory, University College London, explained, “We knew that solar flares can impact a vast area on the Sun, sometimes leaving behind mysterious ‘dark patches’. Using Hinode, for the first time we have been able to train a speed camera on the material in these dark areas – which can be twenty times the diameter of the Earth."

"We have witnessed material flowing from the dark patch in the wake of the flare, feeding the particle flow that can be hazardous for anything in its path as it hurtles through space at 2000 times the speed of a fighter plane.”

These dark areas fade away after the flare, over several days. “In the long term, understanding solar storms in this new level of detail will allow us to make better predictions of ‘space weather’ storms. This is critical for satellite telecommunications, which we now take for granted”, she adds.

The Hinode Science meeting is taking place at Trinity College Dublin from 20 to 24 August, and is hosted by the Solar Physics team. The team is led by Peter Gallagher and is funded by Science Foundation Ireland and ESA.

Posted by Casey Kazan.