I am loving this. Scientists and engineers have collaborated on a system which can give real-time information on incoming solar flares, blasts of radiation that can harm astronauts and even incur damage on Earth.
The Sun has a magnetic field which is tied in, connected, with the material making up the Sun's surface. The magnetic field can shape the material, which in turn can coil up and tangle the loops of magnetism piercing the Sun's surface. Like tightly compressed springs, the loops of magnetic energy can build up huge amounts of energy, and this energy can be released in an explosion of mind-numbing scale called a solar flare.
The details are complex, but the explosion dwarfs the entire Earth's nuclear arsenal. If the flare is aimed our way, a wave of high-energy subatomic particles marches across the solar system, slams into our magnetic field here on Earth, and can cause all sorts of havoc. The particles can irradiate astronauts, and can induce electrical currents on the Earth's surface, disrupting power grids.
Obviously, it would be helpful to know when something like that is headed our way.
It so happens that a flare gives us a warning before the particle blast wave gets here. Electrons in the flare can be accelerated to huge speeds, just a hair under the speed of light, and they arrive on Earth as much as an hour or so before the main bulk of the particle radiation. By detecting these electrons, a warning can be sent out to any astronauts performing an EVA (spacewalk), or, in the future, who happen to out on the lunar surface. An hour may not seem like much, but it's enough time to get back inside the space station or protective structure if it's needed.
The electrons are detected by the COSTEP (Comprehensive Suprathermal and Energetic Particle Analyzer) instrument on board SOHO, that venerable bastion of NASA and ESA solar science. It has been capable of detecting these electrons for years, but only in the past few weeks has this turned into a real-time method of alerting people on an incoming flare.
Space weather -- the variable nature of the particle and electromagnetic radiation streams from the Sun -- is an important business. Multi-million dollar satellites can get fried by solar flares or the even more dangerous Coronal Mass Ejections, not to mention the danger to astronauts' health (which I mentioned twice, actually). Having a real-time warning will be one of the most useful tools in the kit for space travelers and those who tend to them. This is a fantastic step forward in our exploration of space!
And I have to mention... I wrote an entire chapter about dangers from the Sun in my upcoming book Death from the Skies. I had a lot of help from solar scientists, and it really gave me an appreciation for just how important -- and dangerous -- solar flares and CMEs are. That no doubt has fueled my enthusiasm for hearing this news!