US Naval Observatory Update US Naval Observatory Update
U.S. Naval Observatory Website Alternatives
In Investigation 2.2, Measuring Temperature and Daylight, and Investigation 2.4, Observing the Moon, the US Naval Observatory (USNO) site is suggested to obtain daylight or darkness data over the course of a year. It is also used in Investigation 4.2, Daylight through the Year, to obtain the amount of daylight for each day for a given year. USNO is updating their site and many parts are currently unavailable, including this page. Please refer to these alternate sites to help find the data for this part of the investigation.

NOAA Solar Calculator

Sunrise, sunset, daylight in a graph

The U.S. Naval Observatory site for Sun and Moon data continues to undergo modernization efforts as of February, 20201. They had hoped to have the site operational by Fall 2020, but due to the impact of COVID-19, this project has been delayed. We will update FOSSweb when the site is accessible again. If you would like to see if the site is working again now, you can access it here:

U.S. Naval Observatory