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Helios

World 02 · terrestrial planet

Venus

A bright world hidden beneath crushing clouds.

Venus is close to Earth in size, but its dense carbon-dioxide atmosphere drives a runaway greenhouse effect and extreme surface pressure.

Layered editorial atmosphere. The visible cloud envelope is not a direct surface view.

Order from Sun
2
World type
Terrestrial

Atmospheric weight

An Earth-sized world sealed beneath clouds

Venus demonstrates that similar size does not imply similar conditions. Its dense carbon-dioxide atmosphere changes pressure, heat and visibility together.

01

Heat

The atmosphere is the engine of the surface climate

Venus is the hottest planet even though Mercury is closer to the Sun. A runaway greenhouse effect traps heat beneath a massive carbon-dioxide atmosphere.

The temperature shown by Helios is a surface reference, not a cloud-top value and not a present-time measurement.

02

Direction

A slow world turning backward

Venus rotates in the retrograde direction relative to most planets. Its rotation is so slow that the relationship between a sidereal rotation and a solar day is deeply unintuitive.

The page separates day and year values instead of compressing them into one ambiguous number.

Mean radius

6,051.8km

12,104 km equatorial diameter

Solar day

2802h 00m

Retrograde rotation

Temperature reference

464°C

Global surface reference, not local weather

Reference signals

The conditions that define this world

A dense carbon-dioxide atmosphere with sulfuric-acid clouds.

Atmosphere

Carbon dioxide and sulfuric-acid clouds

The cloud deck hides the solid surface from ordinary visible-light observation and makes atmospheric layers central to every description of Venus.

Surface

Solid ground under extreme pressure

Venus is terrestrial, not a gas giant. Its rocky surface exists beneath the dense atmosphere, where pressure and heat dominate the environment.

Moons and rings

Neither companion nor ring system

The dated reference catalog records no recognized moons and no planetary rings.

Axial tilt
3°
Recognized moons
0 · 2026-07-17
Rings
Venus has no ring system.
Atmosphere
carbon dioxide · nitrogen

Personal comparison

Put the numbers against your own body

Gravity, day length and sunlight delay become more understandable when related to an Earth reference.

Your Earth reference

Nearly Earth gravity, radically un-Earth conditions

The scale reading would be close to Earth's, but that familiar number says nothing about the crushing atmosphere, heat or absence of breathable air.

kg

Use a value from 0 to 1,000 kilograms.

Venus scale equivalent

—kg

This is an Earth-style scale equivalent. Your mass does not change, and a giant-planet value refers to a defined atmospheric level rather than a place to stand.

Earth gravity90.4%surface-reference ratio
Solar-day difference2778h 0mcompared with 24 hours
Sunlight travel6.02 minaverage orbital distance

Exploration record

How we learned to read this planet

Mission summaries are tied to dated official records and are not presented as live telemetry.

  1. 01

    Completed radar orbiter

    Magellan

    Magellan used synthetic-aperture radar to map Venus through its clouds and produced the first near-global view of its surface.

  2. 02

    Future atmospheric probe

    DAVINCI

    DAVINCI is designed to examine Venus from above the clouds to the surface, including atmospheric chemistry, pressure, temperature and descent imaging.

Scientific limits

What these values do—and do not—describe

Reference values keep their definition, source and date context. Editorial diagrams are separated from measured planetary data.

Sources and provenance

NASA mission media

Venus, through a mission archive

Every preview comes from the reviewed NASA media list for that world. A failed request can only fall back to media curated for Venus.

Venus - Magellan and Arecibo Comparison

Venus - Magellan and Arecibo Comparison

This image shows a comparison between NASA Magellan image right and the highest resolution Earth-based Arecibo radar image of Venus.…

NASA/JPLNASA media details
Venus - Comparison of Venera and Magellan Resolutions

Venus - Comparison of Venera and Magellan Resolutions

These radar images show an identical area on Venus (centered at 110 degrees longitude and 64 degrees north latitude) as imaged by the U.S. NASA Magellan spacecraft in 1991 (left)…

NASA/JPLNASA media details
Venus - Comparison of Initial Magellan Radar Test and Data Acquired in 4/91

Venus - Comparison of Initial Magellan Radar Test and Data Acquired in 4/91

This image compares NASA Magellan data acquired in August 1990 during the initial test of the radar system black and white insets with data acquired by the spacecraft in April…

NASA/JPLNASA media details
Latest availableNASA Image and Video Library