Our Solar System (Inner Planets)

Graduation Requirements
Science Earth and Space
Equipment/Materials Needed
No special equipment or materials are required

Humanity's interest in the heavens has been universal and enduring. Humans are driven to explore the unknown, discover new worlds, and push boundaries.

Badge Completion Requirements

Introduction: Inner Planets

The inner planets are rocky and terrestrial, composed mostly of silicates and metals, whereas the outer planets are gas giants. The inner planets are also much more closely spaced than their outer Solar System counterparts. In fact, the radius of the entire region is less than the distance between the orbits of Jupiter and Saturn.

This region is also within the “frost line,” which is a little less than 5 AU (about 700 million km) from the Sun. This line represents the boundary in a system where conditions are warm enough that hydrogen compounds such as water, ammonia, and methane are able to take liquid form. Beyond the frost line, these compounds condense into ice grains. Some scientists refer to the frost line as the “Goldilocks Zone” — where conditions for life may be “just right.”

Generally, inner planets are smaller and denser than their counterparts and have few to no moons or rings circling them. 


The smallest of the planets and the closest to the sun, but not the hottest

Please review the material provided by NASA



Mercury like all of the inner planets is a solid sphere of rock. Mercury is about the size of our moon and spins very slowly.


What planet in our solar system has the greatest density?

Explain the extreme differences between the hot and cold sides of Mercury

Does Mercury show signs of H2O (water) ice?

Discuss the motion of the sun if you were standing on Mercury

Name the space explorer that visited Mercury

Please develop and submit a presentation demonstrating your understanding of Mercury. Please include the above prompts in your presentation


Venus is the second planet from the Sun, orbiting it every 224.7 Earth days. It has the longest rotation period of any planet in the Solar System and rotates in the opposite direction to most other planets. It does not have any natural satellites. 

Please review the following material provided by NASA:




Please review the following :


Discuss the reasons that individuals named Earth and Venus "twin sisters"

Explain why if Mercury is closer to the Sun why Venus is hotter

Explain panspermia and how Venus may have contributed to the hypothesis

Discuss the necessity of a magnetic field for life to exists


Please develop and submit a presentation demonstrating your understanding of Venus. Please include the above prompts in your presentation


The place among the vastness of the universe that we call home

Please review the material provided by NASA




We'll spend a great deal more time with the topic of Earth. However, we need to appreciate Earth as part of the Solar System

Please review the following:







Discuss the possibility of the "flat Earth" hypothesis 

Explain the time when Earth is closest to the sun and furthermost from the sun

Explain why we incorporate Leap Year once every four years

Discuss why the sun is higher in the sky in the summer and lower in the winter

Please develop and submit a presentation demonstrating your understanding of the planet Earth. Please include the above prompts in your presentation


The fourth planet from the Sun, Mars is a dusty, cold, desert world with a very thin atmosphere. ... Mars is one of the most explored bodies in our solar system, and it's the only planet where we've sent rovers to roam the alien landscape. 

Please review the material provided by NASA:




Here are five other fascinating facts about Mars.

1. Color: It’s called the Red Planet because its iron-rich dust gives it landscape a rusty-red color.

2. Diet planet: Mars’s gravity is 38 percent of Earth’s. So if you weigh 60 pounds here, you’d weigh about 23 pounds there.

3. Climate change: At the equator, Mars is a comfortable 80 degrees Fahrenheit, but the temperature at its poles can get down to 199 degrees below zero.

4. In the air: Mars’s atmosphere is mostly carbon dioxide with traces of nitrogen and argon. Earth’s atmosphere is a mixture of nitrogen, oxygen, and other gases.

5. Longer days: A Martian day is about 40 minutes longer than a day on Earth.


Identify two Mar's robot explorers

Explain H2O (water) on Mars

Discuss why Mars is a special place for us to explore

Explain why the Mars sky is blue at dawn and sunset while red during the day

Does Mar's have moons?

How would you land a rover on Mars?

Discuss how methane plays a role in determining if life exists on Mars

Please develop and submit a presentation demonstrating your understanding of Mars. Please include the above prompts in your presentation