Introducing KNOVA — A free reading app with curriculum-aligned passages on History & Science for Grades 3-8Learn More →

Compasses and Navigation — Reading Comprehension

No ratings yet

Premium Resource

Grades

Standards

MS-PS2-3

Rate this resource

Send Feedback / Report an Issue

About This Reader

This comprehensive science passage for grades 6-8 explores how compasses work and their ongoing importance for navigation. Students will learn about the interaction between compass needles and Earth's magnetic field, the concept of magnetic north versus true north (including magnetic declination), and the historical significance of compasses in exploration, trade, and migration. The passage also connects the topic to modern technology, such as GPS, and explains why compasses remain valuable tools. The content aligns with NGSS standard MS-PS2-3 and encourages scientific thinking by explaining mechanisms, presenting real-world cases, and integrating vocabulary. Activities include a glossary, differentiated passage, Spanish translation, multiple-choice quiz, writing prompts, and graphic organizers. Audio integration supports diverse learners. Keywords: compass, magnetic field, navigation, GPS, declination, MS-PS2-3.

CONTENT PREVIEW

compass, map, navigation, travel, orientation, map of the world, earth, continents, north, compass direction, compass, compass, compass, compass, compass, earth, earth — "Compasses revolutionized navigation, enabling travel without landmarks." Image by beasternchen / Pixabay.

Compasses are essential tools for finding direction and have played a key role in exploration and navigation for hundreds of years. A compass needle always points toward magnetic north, not true north, because it aligns with Earth’s magnetic field. Understanding how and why compasses work can help us see their importance—not just in the past, but in today’s world where GPS and digital maps have become common.

How Compasses Work: The Science of Magnetism
A compass contains a small, lightweight magnet called the needle. This needle is free to rotate on a pivot. Earth itself acts like a giant magnet, with invisible lines of force called magnetic field lines stretching between its magnetic north and south poles. The compass needle aligns with these field lines, so one end always points toward Earth’s magnetic north pole. However, Earth’s magnetic north is not the same as its geographic north pole. The difference between these is known as magnetic declination, which varies depending on where you are in the world. For example, in New York City, the compass points about 13 degrees west of true north. Pilots and navigators must adjust for magnetic declination to avoid getting off course.

Historical and Modern Uses of Compasses
Compasses changed history by allowing sailors and travelers to navigate across oceans and deserts, even when there were no landmarks. They were vital for trade routes, exploration, and migration. Today, we often use Global Positioning System (GPS) devices, which use satellites to give precise locations. But compasses remain valuable, especially when electronic devices fail or batteries die. Hikers, pilots, and scientists still use compasses for reliable direction-finding. Modern compasses may include features like adjustable declination settings, sighting mirrors, and luminous dials for night use.

Using a Compass: Reading and Applications
To use a compass, hold it flat and steady. The needle will settle and point north. The rotating compass housing is marked with degrees from 0° to 360°, allowing users to measure bearings and navigate with a map. To account for declination, users must add or subtract the local declination value from their bearing. Accurate use of a compass requires practice and knowledge of local magnetic variation. Compasses are also used in scientific research, such as studying animal migration, since many species use Earth’s magnetic field to navigate.

Understanding compasses connects to broader scientific principles: it’s an example of how physical forces like magnetism shape technology and society. Compasses are a simple yet powerful tool showing how science helps us solve real-world problems.

Interesting Fact: Earth’s magnetic field is constantly changing; the magnetic north pole has moved nearly 990 kilometers (over 600 miles) in the past 200 years!

What does a compass needle align with to show direction?

Earth’s magnetic fieldThe sun’s positionThe nearest mountainThe ocean currents

What is the main difference between magnetic north and true north?

Magnetic north is where the compass points, true north is the geographic North PoleMagnetic north is always east of true northTrue north changes every yearThere is no difference

Why must navigators adjust for magnetic declination?

To avoid getting off courseTo find water sourcesTo measure altitudeTo see at night

Which device uses satellites to provide precise locations on Earth?

Global Positioning System (GPS)AltimeterBarometerThermometer

What is magnetic declination?

The angle difference between magnetic north and true northThe change in temperature over timeA measure of how bright something isThe speed of the compass needle

In the passage, what does the compass housing do?

It contains the dial and degree markings for navigationIt points to the sunIt holds water for balanceIt charges the compass battery

What is an example of a modern use of a compass mentioned in the passage?

Helping scientists study animal migrationMeasuring rainfallPredicting earthquakesCooking food

Which is NOT a feature of some modern compasses?

Heated dialsAdjustable declination settingsSighting mirrorsLuminous dials

True or False: Magnetic north and true north are always the same place.

TrueFalse

True or False: Compasses are still useful today, even with GPS technology.

TrueFalse