(From NASA, http://www-istp.gsfc.nasa.gov/Education/Intro.html )

Welcome to the Radio and Space Plasma Physics Group.
Please feel free to ask if there is anything you do not understand or would like to learn more about.

RASPP is at the forefront of research into the interaction between the planetary environment and the Solar wind. The most spectactular evidence of this aurora are the aurora which occur in the regions surrounding both the north and south poles.

The sun continously emits a stream of particles into the space around it, this is what we call the 'solar wind'. The particles flow out towards the planets at speeds of the order of 100s of kilometres per second. These particles interact with the magnetic field and atmosphere of the earth. The sun emits electromagnetic radiation at all wavelengths including visible light, click here to see the sun at different wavelengths. The sun's magnetic field extends into the space of the solar system, beyond the sun it is known as the 'interplanetary magnetic field' or IMF for short.

The sun can also have violent episodes, solar flares and coronal mass ejections are energetic releases of radiation and particles respectively. These are often directed towards the earth and can trigger geomagnetic storms. NOAA (the American National Oceanic and Atmospheric Administration) has a classification system for geomagnetic storms (amongst other things). Sudden changes in the IMF can also set off geomagnetic activity, in general if the Bz component (this goes up and down parallel to the sun's magnetic axis (if the coordinates are given in GSM)) of the IMF is southwards pointing (negative values) then we can expect more geomagnetic activity.

The aurora or 'Northern Lights' (although they also occur in the far south too!) as they are often known, are the most obvious sign of solar activity seen here at the earth. These beautiful displays of glowing lights normally seen at high latitudes can be seen as far south as London when a severe geomagnetic storm is in progess. The aurora over Liverpool can be seen here.