---
source: https://iinventedlight.com/library/notes/venus-basics.md
title: "Venus basics: the hottest planet"
license: CC-BY-4.0
license_url: https://creativecommons.org/licenses/by/4.0/
source_license: "US government work, public domain; restated in our own words"
attribution: "Summary by iinventedlight (AI-assisted). Sources: NASA, Venus: Facts, US government work, public domain; NASA, Venus, US government work, public domain."
author: "iinventedlight (synthesis of cited sources); text drafted with AI assistance"
date: 2026-11-04
status: published
checked_on: 2026-11-04
as_of: 2026-11-04
confidence: medium
untested: "No observation or experiment was done; only the fetched government pages were read."
category: coverage-gaps
topic_area: "science-explain: astronomy and space"
tags: science, astronomy, venus, planets
sources:
  - id: S1
    title: "Venus: Facts"
    publisher: NASA
    url: https://science.nasa.gov/venus/venus-facts/
    accessed: 2026-11-04
    license: "US government work, public domain"
  - id: S2
    title: "Venus"
    publisher: NASA
    url: https://science.nasa.gov/venus/
    accessed: 2026-11-04
    license: "US government work, public domain"
---
# Venus basics: the hottest planet

## Short answer
Venus is the second planet from the Sun and Earth's closest planetary neighbor. It is the hottest planet in the solar system, hotter than Mercury, because its thick clouds trap heat; the surface is hot enough to melt lead. [S1][S2]

## Key points
- Sometimes called Earth's twin because of its similar size. [S1]
- After the Sun and Moon it is the third brightest object in the sky. [S1]
- It spins slowly, in the opposite direction to most planets. [S1]
- Mariner 2 flew past Venus in 1962, the first spacecraft to visit another planet. [S2]

## Claims
- id: C1
  claim: Venus is the hottest planet in the solar system.
  source: S1
  evidence: "It's the hottest planet in our solar system"
- id: C2
  claim: Venus's surface is hot enough to melt lead.
  source: S2
  evidence: "It has a surface hot enough to melt lead."
- id: C3
  claim: Venus is the third brightest object in the sky.
  source: S1
  evidence: "Venus is the third brightest object in the sky after the Sun and Moon."
- id: C4
  claim: Mariner 2 was the first spacecraft to visit another planet, passing Venus.
  source: S2
  evidence: "NASA's Mariner 2 was the first spacecraft to visit any planet beyond Earth"

## Sources
- [S1] Venus: Facts. NASA. https://science.nasa.gov/venus/venus-facts/ . License: US government work, public domain. Accessed 2026-11-04.
- [S2] Venus. NASA. https://science.nasa.gov/venus/ . License: US government work, public domain. Accessed 2026-11-04.

License: this note is CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Summary by iinventedlight (AI-assisted).