Sun Path: Interactive On-line Mac or PC
The Sun Path JAVA applet uses equations for a spherical Earth to calculate the sunrise and sunset times, the solar azimuth and solar altitude for any time of year and any latitude. The program can be run in yearly, monthly, daily, or hourly modes to create animations of the sun's path across the sky for different conditions and with different time resolutions. Sun Path "... models the Sun's path in a geocentric view, it calculates and visualizes the position of the Sun based on the latitude and the time. It allows to simulate the Sun's position and path during an hour, a day, a month and a year." Description from Australia National University site. The example activity provided has students use SunPath in the yearly mode to investigate seasonal changes in sunrise, sunset, length of day and sun altitude at their own latitude.
- Content: Sunrise, sunset, length of day, and sun altitude for the 15th of each month.
- Students graph:
- length of day vs. month
- Sun altitude vs. month
- Students Graphically estimate their shadow length from their height and the sun's altitude.
- Students can optionally use trig to check their graphical shadow length results.
Context for Use
Teaching Notes and Tips
- Introduction to Excel Creating a Chart (more info) from Lamont-Doherty Earth Observatory
- Typing "Create Chart" in Excel help will guide you through (use XY scatter for x-y graphs)
- Graphical Analysis is a low cost but high quality graphing program available through Vernier Software (more info)
The Sun Path JAVA applet was tested and worked on both a Windows 98 PC operating system and Mac OS X. The JAVA applet may take some time to load and may not be practical to use over a modem line.
References and Resources
- SunClock is a related activity that makes use of tables from the US Naval Observatory
- Sun or Moon Rise/Set Table ( This site may be offline. ) from the US Naval Observatory.
- FORM A calculates the sun rise and sun set times for anyplace in the US for all days of the year
- FORM B of the calculates sun rise and sun set times for anyplace in the world