Schooled! ;-) On Fri, Sep 5, 2014 at 12:55 PM, daniel turner via Utah-Astronomy < utah-astronomy@mailman.xmission.com> wrote:
It's for a very good reason. Astronomers and surveyors who actually do the trigonometry that converts RA/DEC coordinates to ALT/AZ have found that pointing zero to the south makes for a much easier math conversion. So the South as zero has been a convention for these "hard core" science types for a very long time.
Another example is Seiichi Yoshida's excellent comet website.
http://www.aerith.net/comet/weekly/current.html
But of course this frightens some of the supposed gatekeepers of knowledge who insist on rigid conformity and relentless dumbing down. Like in our reoccurring debates about kilometers and kilograms
it's just a colorful fact of life. It won't hurt you and if you ever try to "do the math" with celestial coordinates, you will quickly see why it's done that way.
And you will be running with the big dogs.
DT
BTW, for some reason (can anyone here explain?) MPC's idea of azimuth is 180 degrees off what I think most of us use. So subtract 180 for the azimuth numbers listed to get ones most of us are more used to (i.e. where is says 330, subtract 180 to get 150 in the SE).