I'm so thankful for the navigation books I found at the library that are geared towards kids. When we started this navigation unit, I only had three activity ideas: learn how to use a compass, use a map, and geocaching. Today though, thanks to these books, we took a brief foray into the navigational techniques of long ago and learned some basics about latitude and longitude.
At the last meeting, we talked about how virtually all birds use the sun to navigate, while fewer use the stars. Today, we created a simple astrolabe, which was used by ancient seafarers to find their latitude with the help of the North Star (or Southern Cross for those exploring the Southern Hemisphere).
The astrolabe project idea and instructions came from Tools of Navigation: A Kid's Guide to the History & Science of Finding Your Way. But before we dove into our project, we looked at a globe and talked about the lines of latitude and longitude. We talked about how the equator is measured at 0 degrees and the poles are at 90 degrees, and that there are lines drawn on our globe that run horizontally that help us understand how far north or south we are. Latitude was the focus of our discussion because the astrolabe can only be used to estimate latitude. We did briefly talk about longitude, stating that they were the lines that ran perpendicular to the latitude lines, sharing that it took humans considerably more time to figure out how to measure longitude, and that location can be determined by knowing its latitude and longitude.
The project itself was very easy to pull off - the only material we didn't have on hand were the protractors. Asking the stars to come in the middle of the afternoon was trickier, so instead of using the actual North Star to determine our location, as the project directions instruct, we used other landmarks to get the hang of how to use the astrolabe and how to perform the calculations to estimate latitude. I typed out instructions and sent these home with the Clubbers so that they could try to use them when they are out and about on evening excursions.
And we had fun going through the calculations as well! The Clubbers pondered how their heads (and astrolabes) would be tilted if they were searching for the North Star while standing right on the North Pole, as well as at the equator. At least one of the Clubbers wanted to continue experimenting with different landmarks.