Space Isn't Empty   Beads on a String   Water Sprinklers in Space   What angle does the solar wind hit Earth at? Comet tails Magnetic field rubber band applet? Try to hit the earth (with a tracer, and with a cloud). When do you launch? We can put text here explaining Parker spirals... I expect we both have enough books around we can mine for text. We also need some "inquiry" questions. Two subjects that come to mind are to note that the particles move radially but still give you a spiral, and that the local angle of the spiral changes as you get farther from the sun. I've also given thought to whether I could launch a cloud along the spiral. It seems possible. But maybe I'll save that for part of an NSF $50k proposal.