US Naval Observatory Update US Naval Observatory Update
U.S. Naval Observatory Website Alternatives
The US Naval Moon Phase Calendar is used in Investigation 1 to check the moon phase and moon rise/set times for potential observation days. The US Naval Observatory is currently modernizing their website and many sections are unavailable. You can use this alternate site until the US Naval Observatory site is available:

Moonrise and Moonset Calculator

In the "Extending the Investigation" section for Investigation 2, the activity titled, "Measure a Shadow" has students refer to the US Naval Observatory site (Sunrise and Sunset Times) to help them find their local noon. In Second Edition, Investigation 3.2, Day Length, students will again refer to the site to acquire sunrise and sunset data. Please use these alternate sites to help find this information.

NOAA Solar Calculator

Sunrise, sunset, daylight in a graph

The US Naval Observatory expects to have their site back up and operational no later than April 2020, but it could become available sooner. If you would like to see if the site is working again now, you can access it here:

U.S. Naval Observatory