All About the Planets

Lesson Plan - Get It!

Audio:

There are eight planets in our solar system.

Each of these giant balls of gas, dust, and rock revolves around the sun. The eight planets in the solar system are listed below.

1. Mercury
2. Venus
3. Earth
4. Mars
5. Jupiter
6. Saturn
7. Uranus
8. Neptune

You can remember the order of the planets with the saying My Very Educated Mother Just Served Us Nachos. The first letter in each word represents the name of a planet.

• Are you wondering what happened to Pluto?

Pluto was the ninth planet in our solar system until 2006. In 2006, scientists redefined what it takes to be considered a planet by creating a list of new criteria. Criteria for being considered a planet include the following.

• It must orbit the sun.
• It must have sufficient mass to assume a nearly round shape.
• It must clear the neighborhood around its orbit.

According to scientists, every criterion must be met to be considered a planet. Pluto did not meet the criterion known as the "cleared the neighborhood" criterion.

Failure to meet this criterion means Pluto is gravitationally dominant in its region of space, and there are no other celestial bodies — other than its own satellites — near it. Since this revelation, Pluto has been known as a dwarf planet.

Even though Pluto lost its status as a planet in 2006, all the other planets in our solar system meet the three criteria and are still classified as planets.

The eight planets are divided into two groups; the rocky planets and the gas giants.

The rocky planets, also known as terrestrial planets, are the four inner planets: Mercury, Venus, Earth, and Mars. These planets are much smaller than the outer planets and are made primarily of rock and metal.

Watch the video below to learn more about the inner, rocky planets.

The four outer planets are called the gas giants. These planets are Jupiter, Saturn, Uranus, and Neptune.

These planets are primarily made of gas and, because of their distance from the sun, are much colder than the inner planets.

Watch the video below to learn more about the gas giants.

After watching the video clips, compare and contrast what you learned about the two types of planets.

• How are the planets similar?
• How are they different?

On a separate piece of paper, draw the following chart.

Explore The Planets online for help completing the chart. Click on each planet to read information, look at pictures, and examine a timeline.

When your chart is complete, consider these questions.

• Why is the earth the perfect place for humans?
• What happens to the temperature on each planet as you move farther away from the sun?
• Which planet has the most moons?
• Which planet has the most rings?
• Which planet do you find most interesting? Why?

Orbit on over to the Got It? section for some out-of-this-world challenges!