Ch 2: The Basics of Astronomy

About This Chapter

Check out this chapter on astronomy fundamentals if you need help with your homework or want to supplement what you're learning in class. This chapter is comprised of short, easy-to-navigate video lessons and self-assessment quizzes you can access 24 hours a day from your computer or mobile device.

The Basics of Astronomy - Chapter Summary

Our instructors outline the basics of astronomy for your review in this engaging chapter. You can watch informative videos covering subjects such as the planets, lunar eclipses and precession. Even the most challenging topics are easy to understand when they're presented in our professionally designed learning materials. We've included quizzes with the lessons and a comprehensive test at the end of the chapter to help boost your confidence and ensure you've fully understood what you've learned. If you need any help from an instructor, reach out to one by submitting your questions through the Dashboard. Once you finish watching these videos, you should be able to:

  • Explain the horizon coordinate system and the equatorial coordinate system
  • Identify important points on the celestial sphere
  • Outline the cycle of seasons in astronomy
  • Discuss the orbits and visibility of the planets of the solar system
  • Define precession and its importance
  • Describe how distance and angular size are used to measure objects in the sky
  • Detail the different types of lunar eclipses
  • Explain what happens during a solar eclipse

9 Lessons in Chapter 2: The Basics of Astronomy
Test your knowledge with a 30-question chapter practice test
The Horizon Coordinate System

1. The Horizon Coordinate System

This lesson will describe a celestial coordinate system known as the horizon system or altazimuth system, as well as important terms such as altitude, azimuth, zenith, and angular distance.

The Equatorial Coordinate System

2. The Equatorial Coordinate System

This lesson will teach you about the fundamentals of the equatorial system, including declination, right ascension, the vernal equinox, angular diameter, and celestial equator.

Important Points on the Celestial Sphere

3. Important Points on the Celestial Sphere

This lesson will discuss some important points and lines located on the celestial sphere, including the zenith, nadir, celestial equator, meridian, and north and south celestial poles.

The Cycle of the Seasons in Astronomy

4. The Cycle of the Seasons in Astronomy

This lesson will explain to you why the Earth has different seasons, what the equinoxes and solstices are, their names, and if the distance the Earth is from the Sun influences the seasons.

Planets of the Solar System: Orbits & Visibility

5. Planets of the Solar System: Orbits & Visibility

This lesson will tell you which planets in our solar system you can see with the naked eye and which ones you cannot. You'll also learn how they appear to move in our sky and why we can see them in the first place.

What is Precession?

6. What is Precession?

You've probably heard of the term precession. But what is this really? And what significance does it have to our night sky? This lesson will explain what it is and what it causes.

Measuring Objects in the Sky: Angular Size & Distance

7. Measuring Objects in the Sky: Angular Size & Distance

This lesson will teach you about the celestial sphere, angular distance, angular size and diameter, arc minutes, and arc seconds. You'll also learn some neat tricks on how to use your own hands to measure these.

Lunar Eclipse: Definition & Types

8. Lunar Eclipse: Definition & Types

This lesson will teach you about the lunar eclipse. You'll learn the difference between a penumbral, partial, and total lunar eclipse, and see what totality means with respect to a total lunar eclipse.

What Is a Solar Eclipse?

9. What Is a Solar Eclipse?

This lesson will describe what a solar eclipse is, why it's possible, when a partial or a total one will occur, and what cool effects occur during one.

Chapter Practice Exam
Test your knowledge of this chapter with a 30 question practice chapter exam.
Not Taken
Practice Final Exam
Test your knowledge of the entire course with a 50 question practice final exam.
Not Taken

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