Abstract

Do you ever wonder how pirates sailed the seven seas? The two most important things a pirate could have (besides a parrot and big hat) were a compass and an accurate watch. Ancient navigators didn't know about compasses, so how did they know where they were going? Could they have used the stars to know which way to go?

Objective

In this experiment you can determine which stars to use to navigate in each hemisphere of the globe.

Introduction

Does your new family car have a global positioning system, or GPS unit? This amazing device can tell you where you are going while traveling by car, airplane, boat or train. Most modern navigation is done using GPS, which uses information from satellites to tell you where you are and how to get to a particular destination. The information from a GPS is so accurate that it can be used to program an autopilot to conduct routine navigation. A GPS will tell you a location based upon latitude and longitude. The latitude tells you how far north or south you are, while longitude tells you how far east or west you are.

How did people navigate before modern technology?

• Polynesians: By far, the most exceptional ancient navigation was by the Polynesians, who navigated thousands of miles throughout the Pacific Islands. They did not use any instrumentation to navigate. They used a type of celestial navigation called Wayfaring, which means that they used information about the stars, sun, moon, planets, ocean and tradewinds to know which way to go. They built boats with a system of rungs that would line up with key stars on the horizon for the navigator to tell direction. It took many years to train a navigator. The Hawaiian Star Compass was an incredibly accurate way to navigate. By developing this navigation system, the ancient Polynesians were way ahead of their time.
• Vikings: The Vikings primarily used coastal navigation, which means that they kept land in sight and knew to travel in one particular direction along the coast. Occasionally they would navigate long distances across the Atlantic Ocean in the summer. During these voyages they could not have used stars to navigate because at such northern latitudes the sun never sets during the summer months. Instead they used a sun compass, which could tell them direction by casting a curved shadow onto a disk with notches carved on it.
• Ancient Greeks: The ancient Greeks learned to voyage around Europe and the Mediterranean Sea. Two major advances in navigation were made by Ptolemy, a famous Greek astronomer. Ptolemy was the first to make maps using stories from travelers and sailors. He also was the first to use latitude and longitude to tell position on a map.
• Europeans: Eventually, Europeans learned to navigate using a magnetic compass and an accurate clock. How did they navigate before the discovery of the compass? They had the advantage of using Ptolemy's maps to show them where to go and primarily used coastal navigation. To orient themselves they used basic celestial navigation, which means that they used information from the stars and from the sun to orient themselves. The rising and setting of the sun could orient them East or West. The positions of navigational stars could orient them North and South.

Which stars are important for navigation? There are several, but the most famous navigational stars are the North Star, called Polaris, and the Southern Cross. The North Star (Polaris) is a part of the constellation Ursa Minor, commonly known as the Little Dipper. The Southern Cross is a constellation of four stars called Crixa, two of which point towards the celestial south pole.

Depending on where you are in the world and where you want to go, one navigational star will be more important than the other. In this experiment you can use the internet to find a star chart from anywhere in the world. You can look for the North Star and the Southern Cross from different locations around the world to see which star to use for navigation.

Terms and Concepts

To do this type of experiment you should know what the following terms mean. Have an adult help you search the Internet, or take you to your local library to find out more!

• Navigation
• Latitude
• Longitude
• North Star (Polaris)
• Little Dipper (Ursa Minor)
• Southern Cross (Crixa)
• Northern Hemisphere
• Equator
• Southern Hemisphere

Questions

• Which stars are useful in the Northern Hemisphere?
• Which stars are useful in the Southern Hemisphere?
• How about along the equator?

Materials and Equipment

• Computer with internet access
• Star chart website or app
• Printer
• A globe or world map

Experimental Procedure

Variations

Careers

If you like this project, you might enjoy exploring these related careers:

Related Links

• Science Fair Project Guide
• Other Ideas Like This
• Astronomy Project Ideas
• My Favorites

Cite This Page

General citation information is provided here. Be sure to check the formatting, including capitalization, for the method you are using and update your citation, as needed.

MLA Style

APA Style