← The Solar System
Difficulty: ●○○○○

The Inner Planets

Mercury, Venus, Earth, and Mars — the four small, rocky planets closest to the Sun.

PERSONAL FIELD NOTE

Capture an insight

💡 Analogies

Think of the inner planets as four siblings who grew up in the same neighborhood but turned out very differently — same rocky ingredients, wildly different results.

⚠️ Common Misconceptions

Myth: Mars is hot because it's red.

Reality: Mars is actually very cold! Average temperature is about -65°C. The red color comes from iron oxide (rust) on its surface, not heat. It's farther from the Sun than Earth and has a very thin atmosphere.

🧪 Test Your Understanding

Which is the hottest planet in our solar system?

Which inner planet has the tallest volcano in the solar system?

🧠 Quick Review

Why is Venus hotter than Mercury?

Click to reveal answer

📖 Sources

institutional
The Solar System — NASA Science (2024)
textbook
Planetary Sciences — Imke de Pater, Jack Lissauer (2015)
textbook
The New Solar System — J. Kelly Beatty et al. (1999)