How Astronomers Know — Evidence Lab
Compare the Planets
- Estimated time
- ~10 min
Saved locally on this device
Learning goals
- Reading a bar chart lets you compare planet sizes at a glance without having to remember every number.
- 5-ESS1-1 — Students compare apparent brightness of stars at different distances and support an evidence-based claim.
Help & glossary
- Use the hint ladder before checking your answer — hints get more specific.
- Incorrect answers can be retried. Feedback explains why.
- Constructed responses (CER) are self-checked — nothing is sent to a server.
Question 1 of 2
Look at the chart of planet diameters. Which planet is the largest?
A bar chart shows how big each planet is by how tall or long its bar is. The taller the bar, the bigger the planet.
| Planet | Diameter (km) |
|---|---|
| Mercury | 4,879 |
| Venus | 12,104 |
| Earth | 12,756 |
| Mars | 6,792 |
| Jupiter | 142,984 |
| Saturn | 120,536 |
| Uranus | 51,118 |
| Neptune | 49,528 |
Bar chart showing the diameter of each planet in kilometers. Bars from smallest to largest: Mercury, Mars, Venus, Earth, Neptune, Uranus, Saturn, Jupiter.
Sources
- Planetary Fact Sheet — NASA — NASA (Goddard) · NASA Goddard Space Flight Center · Accessed 2026-09-01