Welcome to the NavList Message Boards.

NavList:

A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding

Compose Your Message

Message:αβγ
Message:abc
Add Images & Files
    or...
       
    Reply
    Re: Moon Rise - I'm Missing Something
    From: Frank Reed
    Date: 2020 Aug 10, 11:54 -0700

    This is an interesting problem of definitions. What do we mean by "time of moonrise today"? Suppose it's a Monday evening, and you're preparing for a night of astrophotography, and you want to make sure you get some Milky Way photos before moonrise. Should you look up the time or moonrise for today or for tomorrow? The right way to do this in the year 2020 is with a simulation app, e.g. Stellarium. Then you won't have any doubts. But suppose you're using a list-based source, like the Nautical Almanac, or a source that interrogates a list. You want to find out when the Moon will rise "tonight". But by this you mean that you want to find out when the Moon will rise before the next sunrise which by standard civil dates is actually parts of two different calendar days. So if it's Monday evening, you need to know when the Moon rises on Tuesday morning, right? But what happens when the time of moonrise is close to midnight? It can get a bit tricky! 

    You know you can ask a smartphone simple questions. On Android, if you do the "OK Google" thing and ask for the time of sunrise tomorrow, it happily replies with the time. If you ask for the time of moonrise, it punts (at least in my experiment just now) and sends you to some websites. On iOS, Siri obliges with the time of sunrise, no surprise, but it also answers the moonrise question. I haven't experimented enough to see how it handles the near midnight cases.

    Frank Reed

       
    Reply
    Browse Files

    Drop Files

    NavList

    What is NavList?

    Join NavList

    Name:
    (please, no nicknames or handles)
    Email:
    Do you want to receive all group messages by email?
    Yes No

    You can also join by posting. Your first on-topic post automatically makes you a member.

    Posting Code

    Enter the email address associated with your NavList messages. Your posting code will be emailed to you immediately.
    Email:

    Email Settings

    Posting Code:

    Custom Index

    Subject:
    Author:
    Start date: (yyyymm dd)
    End date: (yyyymm dd)

    Visit this site
    Visit this site
    Visit this site
    Visit this site
    Visit this site
    Visit this site