Over the course of our ocean unit, the kids discovered how much our knowledge about the ocean has changed over time. Little was known about the ocean even just fifty years ago — let alone hundreds of years ago when explorers were first venturing out. We talked about early navigation techniques and in talked quite a bit about how the stars can be used for navigation. The kids can recognize the Big Dipper, but didn’t really understand how Polaris/the North Star could help navigators in the middle of the ocean.
Polaris, the North Star, could help navigators find their latitude since when you are almost at the North Pole, Polaris appears to be almost directly overhead. The further south you go and the closer you are to the equator; the lower Polaris is to the horizon.
We talked about some of the techniques used by early navigators when they didn’t have the instruments available to us today – in particular the astrolabe. The pages below are in our Ocean Packet.
The kids made their own simplistic astrolabe with a protractor, straw, string and washer.
- Tie a washer on the end of a string.
- Tie the string around the top of the protractor (in the middle). Tape the string in place so it stays exactly in the middle.
- Tape a large straw across the top of the protractor. (The kids will be looking through the straw at the North Star, so a larger straw is better.)
- Have them locate the North Star through the straw. Then have them hold the string in place.
We tried it out during the day picking random things to be our “North Star.”
Our Ocean Packet will be available in the next couple of weeks.
You may be interested in our other Ocean Unit Posts:
- Ocean Unit: 5 Salinity Activities & Why the Ocean is Salty
- Surface Currents, Deep Sea Currents Activities
- Features of the Ocean Floor (coming later this week)
- Ocean, Seas and Straits – Pin Map Printable
If you have younger kids you may be interested in the ocean activities we did when they were preschool and early elementary age:
- Ocean Animals and Their Groups
- Ocean Activities: The Ocean Zones, Layers of the Ocean
- Ocean Activities – diorama
Disclosure: Please note that some of the links in this post are affiliate links, and at no additional cost to you, I will earn a commission if you decide to make a purchase.