Speed as important as size in predicting potentially damaging impacts of coronal mass ejections.

Space weather forecasters need to predict the speed of solar eruptions, as much as their size, to protect satellites and the health of astronauts, scientists have found.

Scientists at the University of Reading found that by calculating the speed of coronal mass ejections (CMEs) when they hit Earth, forecasters could provide more useful early warnings. This would help operators of critical infrastructure such as satellites know if they need to take evasive action or switch off systems to protect them, and warn astronauts when they need to shelter inside shielded parts of the International Space Station.