to tell us about those i am joined by professor tim horbury, from the imperial college london.res and coronal mass ejections are? most of us think of the sun as a fairly boring yellow globe in the sky. but as we study it more we realise it is a dynamic object. solar flares are enormous releases of energy from the sun. they accelerate particles to high energies which can arrive at the earth and damage satellites, and they also release enormous amount of energy and coronal mass ejections. this matter floods out through the solar system and can arrive at the earth and impact us. you are the head of a mission investigating the sun? it is called solar orbiter, being built by the esa at the moment. we will be going closer to the sun than ever before, closer than mercury. we'll measure what comes off the sun and travels past our spacecraft on its way towards the earth. and it is the magnetic fields which are important when it comes to impact on our planet, isn't it? that's right. at imperial college london, we're building the instrument which will measure those magnetic fields in spac