Why is Venus hotter than Mercury?
Show answer & explanation
Answer: Thick atmosphere traps heat
Mercury has no core — Wrong. Mercury does have an iron core. Venus is hotter because its dense CO₂ atmosphere creates greenhouse effect, not Mercury's internal structure.
Thick atmosphere traps heat ✓ — Correct! Mercury is closer to the sun, but Venus is hotter (~465°C vs Mercury's ~430°C dayside). Venus has extremely thick CO₂ atmosphere (90x Earth's pressure) creating runaway greenhouse effect. Sunlight enters, heats surface, but infrared radiation can't escape—trapped by CO₂ and sulfuric acid clouds. Mercury has almost no atmosphere—no heat retention. Venus is hottest planet despite being second from sun!
Venus is larger than Mercury — Wrong. Size doesn't determine temperature. Venus is hotter because its thick CO₂ atmosphere creates extreme greenhouse effect trapping heat.
More Astronomy & Space questions
- Which gas escapes fastest from Earth's atmosphere as it slowly leaks to space?
- Why is Earth's day getting slightly longer every century?
- Why was Earth's day stuck at 19.5 hours for 1.5 billion years?
- Why might using several small reactors be better than one giant reactor on the Moon?
- Why is fission likelier than fusion for first Moon bases?
- Why put a lunar reactor away from the habitat?