Comments on: Bah. Research. (Moved to SF) https://habitablezone.com/2012/04/22/bah-research/ Fri, 03 Apr 2026 18:20:54 -0700 hourly 1 http://wordpress.org/?v=3.3.1 By: Ainz https://habitablezone.com/2012/04/22/bah-research/#comment-14639 Ainz Wed, 02 May 2012 06:01:55 +0000 http://habitablezone.com/?p=13878#comment-14639 Just stumbled upon these folks the other day. I have not tried it, but they are a legit C.E. firm, and offer it for free. <a href="http://www.sunposition.com/tables.html" rel="nofollow">Here</a> Scroll down a little to "Ordering Info" Just stumbled upon these folks the other day. I have not tried it, but they are a legit C.E. firm, and offer it for free.

Here

Scroll down a little to “Ordering Info”

]]> By: ER https://habitablezone.com/2012/04/22/bah-research/#comment-14141 ER Mon, 23 Apr 2012 04:06:36 +0000 http://habitablezone.com/?p=13878#comment-14141 For this sort of thing, I recommend http://www.usno.navy.mil/USNO/astronomical-applications/data-services/cel-nav-data?searchterm=celestial+navigation+data Enter the Date, Year, Universal Time and Lat/lon of the location. Just make sure you correct for the time difference between the location of your action and UT, including allowance for Daylight Savings Time. The numbers you need from the table are altitude in degrees above the horizon (Hc), and the Azimuth (Zn) (degrees measured clockwise from true North). Only those celestial bodies above the horizon are listed, although if an object is just below the horizon it may be visible due to atmospheric refraction. The figure in the table is corrrected for refraction, so it will have a negative Hc, indicating below the horizon, but possibly visible. I salute you for taking the trouble. I hate stories set in the tropics where "the full moon rose at midnight". It's like hearing the rockets of space fighters as they make coordinated rudder-and-stick maneuvers in vacuum. For this sort of thing, I recommend

http://www.usno.navy.mil/USNO/astronomical-applications/data-services/cel-nav-data?searchterm=celestial+navigation+data

Enter the Date, Year, Universal Time and Lat/lon of the location.

Just make sure you correct for the time difference between the location of your action and UT, including allowance for Daylight Savings Time.

The numbers you need from the table are altitude in degrees above the horizon (Hc), and the Azimuth (Zn) (degrees measured clockwise from true North).

Only those celestial bodies above the horizon are listed, although if an object is just below the horizon it may be visible due to atmospheric refraction. The figure in the table is corrrected for refraction, so it will have a negative Hc, indicating below the horizon, but possibly visible.

I salute you for taking the trouble. I hate stories set in the tropics where “the full moon rose at midnight”. It’s like hearing the rockets of space fighters as they make coordinated rudder-and-stick maneuvers in vacuum.

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