An active sunspot group that has been blasting solar particles into space from the far side of the sun, will soon be pointed more nearly in Earth's direction. Here's a movie of one of the eruptions, shot by NASA's Solar and Heliospheric Observatory. This one was directed away from the Earth. Those aimed at us, if they're powerful enough, can cause radio interference, satellite damage and disruptions of electrical power grids.

These "coronal mass ejections" can also be a radiation hazard for exposed astronauts. If the sunspots stay active, they could crimp NASA's plans for three upcoming spacewalks by Discovery astronauts.

The "extra-vehiclular activity" is currently planned for Saturday, Monday and Wednesday mornings. If solar storms threaten, NASA can be expected to cancel or postpone any spacewalks and order astronauts to take cover in well-shielded portions of the space station.

Speaking of the International Space Station, here's a cool picture of the station as it flew in front of the sun this week, as seen from Athens, Greece.