Space & Astronomy
SPACE OBSERVATORY / 08

Planet Size Comparison 3D

Compare planetary radii and volumes using a common visual scale.

YOUR OBSERVATORY NOTEBOOK0 / 10plus Moon Landing & Orbital Rescue missions
Planet scale gallery
Drag to rotate · illustrative overview scale
Earth radius6,371 km
Mars radius3,390 km
Volume ratio B / A0.151×
CONTINUE YOUR EXPLORATION

All 12 space activities

Free online planet size comparison 3D

Planet Size Comparison 3D: experiment guide

This browser-based 3d explorer helps you compare planetary radii and volumes using a common visual scale. Designed for Grades 7–12, it turns an abstract idea into a model you can control, measure, reset, and test without signing up.

What you can investigate

Explore Planet radius, scale, volume, relative size by changing the available controls and comparing the model’s visual and numerical evidence. Try one variable at a time, then combine changes to test a stronger explanation.

Planet radiusscalevolumerelative size

How to use this simulation

  1. 1Read the mission and make a prediction before moving a control.
  2. 2Change one variable so its effect is easier to identify.
  3. 3Run the model and record a value, pattern, or visible change.
  4. 4Reset, test a different setup, and explain the result from evidence.

For students, teachers, and independent study

A typical investigation takes 4–8 min. Use it as a lesson demonstration, a guided inquiry activity, a homework experiment, or a quick review. The simulation runs in a modern web browser and does not require an account.

Level
Beginner
Time
4–8 min
Format
3D explorer

Common questions

What does the Planet Size Comparison 3D teach?

Compare planetary radii and volumes using a common visual scale. The main ideas are Planet radius, scale, volume, relative size.

Is the Planet Size Comparison 3D free to use?

Yes. You can run the simulation online for free without creating an account.

How long does the activity take?

Most learners can complete one investigation in 4–8 min. You can repeat it to compare more variables or improve your explanation.