Log out Go to App
Go to App

Learning Materials

Features

Discover

Chapter 2: Problem 27

Seafaring sailors such as Columbus used Polaris for navigation as they sailed from Europe to the New World. When Magellan sailed the South Seas, he could not use Polaris for navigation. Explain why.

Short Answer

Expert verified
Polaris is not visible in the Southern Hemisphere, so Magellan could not use it for navigation in the South Seas.

Step by step solution

01

Understand the Role of Polaris

Polaris, also known as the North Star, is a significant star used in navigation because it is almost directly aligned with Earth's rotational axis. This means it stays nearly fixed in the sky and is located almost directly above the North Pole.
02

Define Geographic Location Concepts

Europe is located in the Northern Hemisphere. When sailing from Europe (like Columbus did), Polaris remains visible in the night sky for navigation because it is situated above the northern horizon.
03

Distinguish the Difference in Hemispheres

Magellan sailed in the South Seas, which are in the Southern Hemisphere. Polaris is not visible in the Southern Hemisphere because it is located on the opposite side of the celestial sphere.
04

Draw the Conclusion

Since Polaris is not visible in the Southern Hemisphere, Magellan could not use Polaris for navigation while sailing in the South Seas.

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Start your free trial

Over 30 million students worldwide already upgrade their learning with Vaia!

Key Concepts

These are the key concepts you need to understand to accurately answer the question.

North Star
Polaris, commonly known as the North Star, holds a special place in celestial navigation.
It is nearly aligned with Earth's rotational axis, so it appears almost stationary in the sky.
At night, when sailors see Polaris, they know they are looking northwards.
This unique position has made it a reliable tool for navigation for centuries.
Unlike other stars, which seem to move due to Earth's rotation, Polaris stays steady.
This constancy helps navigators easily determine direction without needing complex tools or instruments.
Hemisphere Differences
Polaris’s visibility depends greatly on which hemisphere you're in.
If you're in the Northern Hemisphere, you will see Polaris in the northern sky.
This makes it invaluable for navigators in regions like Europe and North America.
However, things change when you cross into the Southern Hemisphere.
In the Southern Hemisphere, Polaris is not visible at all.
This is because it's located above the North Pole, on the opposite side of Earth's celestial sphere.
Sailors like Magellan, who sailed the South Seas, couldn't rely on Polaris for their navigation.
Instead, they had to use other stars and constellations like the Southern Cross to find their way.
Celestial Navigation
Celestial navigation is an ancient practice using stars to determine a ship's position.
Key stars, including Polaris in the North, are vital to this method.
When sailors are out at sea, they often lack landmarks.
Thus, they turn to the sky for guidance.
By measuring the angle between Polaris and the horizon, navigators can determine their latitude.
In the Southern Hemisphere, sailors like Magellan used different constellations.
The Southern Cross constellation is one key star group they used to find their direction.
Geographic Location
Your geographic location on Earth significantly affects which stars you see.
For instance, Europe is located in the Northern Hemisphere.
When Columbus sailed from Europe, he could always see Polaris in the northern sky.
In contrast, the Southern Hemisphere offers a completely different sky.
For sailors in the South, like Magellan, Polaris wasn't an option.
Instead, they had to become familiar with the southern sky, including stars and constellations unique to that part of the world.
Understanding the geographic location helps explain why different navigational stars are needed depending on where one is on Earth.

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

Assume that rain is falling at a speed of 5 meters per second \((\mathrm{m} / \mathrm{s})\) and you are driving in the rain at the same speed, a leisurely \(5 \mathrm{m} / \mathrm{s}(18 \mathrm{km} / \mathrm{h}) .\) Estimate the angle from the vertical at which the rain appears to be falling.

Assume that the Moon's orbit is circular. Imagine that you are standing on the side of the Moon that faces Earth. a. How would Earth appear to move in the sky as the Moon made one revolution around Earth? b. How would the "phases of Earth" appear to you, compared to the phases of the Moon as seen from Earth?

Constellations are groups of stars that a. are close to each other in space. b. are bound to each other by gravity c. are close to each other in Earth's sky. d. all have the same composition.

On the summer solstice in July, the Sun will be directly above ___ and all locations north of __ will experience daylight all day. a. The Tropic of Cancer; the Antarctic Circle b. The Tropic of Capricorn; the Arctic Circle c. The Tropic of Cancer; the Arctic Circle d. The Tropic of Capricorn; the Antarctic Circle

The Sun, Moon, and stars a. appear to move each day because Earth rotates. b. change their relative positions over time. c. rise north or south of east and set north or south of west, depending on their location on the celestial sphere. d. all of the above
See all solutions

Recommended explanations on Physics Textbooks

Force

Read Explanation

Magnetism

Read Explanation

Engineering Physics

Read Explanation

Torque and Rotational Motion

Read Explanation

Thermodynamics

Read Explanation

Fundamentals of Physics

Read Explanation
View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.

Sign-up for free