When the Sun erupts

Vast clouds of magnetic field and charged particle plasma are blasted away from the Sun. We call these eruptions Coronal Mass Ejections (CMEs). We study the magnetic fields in the Sun’s atmosphere during the lead-up to an eruption, to understand the conditions and physical processes that give rise to these gigantic outbursts. Eventually we would like to be able to predict them.

The magnetic fields in the Sun’s atmosphere are amazing structures; the ones we study reach thousands of miles up into the atmosphere, and are revealed by the glowing hot gasses trapped along them. They change over time, with new structures forming and old structures dying. During their lifetime they show signs of being twisted and distorted. This can lead to them becoming unstable, which could explain why CMEs occur.

This area of research is currently high-profile, because CMEs travel out through interplanetary space, interacting with all the solar system bodies they meet, including the Earth. CMEs drive a multitude of processes throughout the solar system, and scientists across the UK are trying to understand them all. The major effect of CMEs on the Earth can be very dramatic. It's known as ‘space weather’.

The latest space project to study CME's is the Hinode mission. It is mainly a Japanese-built spacecraft, but the UK has supplied one of the three principal instruments onboard: an Extreme Ultraviolet (EUV) imaging spectrometer developed by University College London's Mullard Space Science Laboratory.