Here's something I've been wondering about for a while. Rather than using a categorical definition of darkness (e.g. sun more than 5 degrees below horizon) to determine if conditions are acceptable for viewing, it would be nice to have a definition that took into account the expected satellite magnitude (if available). Something like for a mag Y satellite, the sun must be at least X degrees below the horizon where Y is estimated the usual ways and X is computed from Y in some way. Anyone know of such a thing? Cheers, ...eric