Planetary Geology: The Study of Celestial Bodies

An error occurred trying to load this video.

Try refreshing the page, or contact customer support.

Coming up next: Diagenesis in Geology: Definition, Process & Examples

You're on a roll. Keep up the good work!

Take Quiz Watch Next Lesson
Your next lesson will play in 10 seconds
  • 0:01 Geology
  • 0:35 What Is Planetary Geology?
  • 2:51 Planetary Geology Techniques
  • 4:50 Lesson Summary
Save Save Save

Want to watch this again later?

Log in or sign up to add this lesson to a Custom Course.

Log in or Sign up

Speed Speed

Recommended Lessons and Courses for You

Lesson Transcript
Instructor: Margaret Cunningham

Margaret has taught many Biology and Environmental Science courses and has Master's degrees in Environmental Science and Education.

Planetary geology is a field of geology that explores celestial bodies like planets, moons, comets, and asteroids. Scientists use a variety of advanced techniques and procedures to carry out their research on these distant bodies.


Humans have been studying the materials found on Earth for many years. Scientists look at what is in the air, what is on the Earth and what is within the Earth. Geology is the study of the solid earth, including the materials that make up the planet and the processes that shape the planet. Through the study of geology, scientists have learned what our earth is made of, how it changes, and how we can use it to produce things that we need for survival.

What Is Planetary Geology?

In more recent years, scientists have also begun to investigate the geology of the planets and other celestial bodies that make up our solar system. Planetary geology is the study of the solid matter that makes up celestial bodies, such as planets, moons, asteroids, and comets. This branch of geology focuses on the materials that make up these celestial bodies and how the bodies are formed.

Although the word planet is in planetary geology, this field investigates more than just planets. Planetary geology includes the study of all celestial bodies: planets, moons, asteroids, and comets. Let's look at the differences between these celestial bodies. A planet is a large celestial body that revolves around a star. A moon is a celestial body that revolves around a planet. Our planet, Earth, has only one moon, but other planets have multiple moons that orbit around them. Besides Earth, Earth's moon is the only other celestial body that humans have set foot on.

Planets and moons are the larger celestial bodies found in the solar system. Smaller celestial bodies include comets and asteroids. Comets are small celestial bodies made of small rock fragments that are embedded in a mass of ice and frozen gases. Most comets orbit the sun and take several years to complete the journey. There are also comets that have journeys that take up to 3 million years! When a comet gets close to the sun it begins to evaporate, which releases a stream of molecules behind the comets that forms the characteristic tail we see from Earth. Asteroids are small celestial bodies that orbit the sun and are mainly made of rock and metallic components. If asteroids collide with each other they can be thrown off their normal orbits and travel in any direction. This can result in an asteroid colliding with another celestial body, most frequently planets.

Planetary Geology Techniques

Now that we know what planetary geology is and what celestial bodies are, let's examine what exactly planetary geologists study, why they study it, and how they study it.

Planetary geologists study the solid matter that makes up celestial bodies. This means that they study the interior of celestial bodies as well as the surfaces. There are many reasons why planetary geologists study celestial bodies. One main reason is just to learn more about the world around us. We are curious and want to know what else is out there beyond Earth. Planetary geologists also study the composition of celestial bodies to determine how they were formed and if there are any natural resources, such as minerals or energy sources, available within the celestial body. As humans diminish the natural resources on Earth, some people believe that other celestial bodies might provide necessary resources. Another reason planetary geologists study celestial bodies is to determine if there is life on these objects.

To unlock this lesson you must be a Member.
Create your account

Register to view this lesson

Are you a student or a teacher?

Unlock Your Education

See for yourself why 30 million people use

Become a member and start learning now.
Become a Member  Back
What teachers are saying about
Try it risk-free for 30 days

Earning College Credit

Did you know… We have over 200 college courses that prepare you to earn credit by exam that is accepted by over 1,500 colleges and universities. You can test out of the first two years of college and save thousands off your degree. Anyone can earn credit-by-exam regardless of age or education level.

To learn more, visit our Earning Credit Page

Transferring credit to the school of your choice

Not sure what college you want to attend yet? has thousands of articles about every imaginable degree, area of study and career path that can help you find the school that's right for you.

Create an account to start this course today
Try it risk-free for 30 days!
Create an account