Download C# source and ClickOnce installer Needs .NET Framework 2.0
Tidied up a bit, looks a little nicer now. I've set it to open near the mouse, without going off-screen or covering the taskbar, and close on deactivation, so it's more like an overgrown balloon tip than a complete window.
Note: The noon/midnight lines should be fairly accurate (I would guess within an hour, as long as I haven't mucked up anything), but only compared to the actual position of the sun, NOT local time. Daylight savings/summer time, for example, throws things off substantially - the sun doesn't suddenly rise and set an hour earlier/later. The 6am/6pm lines (between the light and dark regions), however, are not intended to match the actual sunrise/sunset, they're just a rough guess (and again, they won't match local time). The day/night regions should actually be shaped something like this.
Yes, more Asteroids stuff is coming, as soon as I get a chance to work on it.