Venus
What is Venus?
Planets· Diameter 12,104 km. A runaway greenhouse makes Venus the hottest planet. It shines as the brilliant morning and evening star, and its day is longer than its year.
📍 Visible from where you are right now — computed in your browser
bearing · altitude · rise time · best time tonight
Where Venus is in your sky right now: https://nowsky.org/solar/sky?sel=venus — location and time set automatically, no login.
Orbit and size
| Diameter | 12,104 km |
|---|---|
| Distance | 0.72 AU |
| Year | 225 d |
| Temp | 464 °C |
Figures are representative approximations. Source: compiled from NASA and IAU public data.
Related events
Frequently asked
- How big is Venus?
- 12,104 km.
- How far is Venus from Earth?
- 0.72 AU.
- In one line, what is Venus?
- Planets — A runaway greenhouse makes Venus the hottest planet.
- Where is Venus in the sky right now?
- Open the sky view for your location and time and it shows the position in the sky right now.
Fifty kilometres up: the most Earth-like place on Venus
Venus's surface sits at 464 °C and 92 atmospheres, but 50 to 60 km up, above the cloud deck, the pressure matches Earth's at sea level and the temperature runs between 0 and 50 °C. It is the only place in the solar system beyond Earth with such conditions, which is why "cloud city" concepts for crewed exploration have resurfaced since the 1970s. In 1985 two Soviet Vega balloons actually drifted at this altitude for two days, carried 10,000 km by the winds.
The clouds at that height are sulphuric-acid droplets, so corrosion is unavoidable, but buoyancy is not a problem: ordinary Earth air, nitrogen and oxygen, floats in Venus's carbon-dioxide atmosphere the way helium does in ours, so a balloon filled with breathable air simply rises. NASA's DAVINCI probe, planned for launch in the early 2030s, will descend through this layer measuring the atmosphere directly.
The planet in depth
Venus was born Earth's twin in size and mass and became the harshest place in the solar system. A CO₂ atmosphere presses down at 96 bar, and a runaway greenhouse holds the surface at 465 °C — hot enough to melt lead, hotter than Mercury at twice the distance from the Sun. The clouds are droplets of sulfuric acid, not water.
It rotates backwards, and slowly: a 243-day spin against a 225-day year. On Venus the Sun rises in the west and sets, one Venusian year later, in the east. Whether a giant impact or tidal braking did this is still unsettled.
Yet Venus remains the brightest thing in our sky after the Sun and Moon. Track the "morning star" swinging between dawn and dusk in the Sky view — and remember it as the case study in where a greenhouse can end.
How Venus became Earth's failed twin reads like a climate-science warning label: nearly identical in size and mass, it sat just close enough to the Sun for its ocean to evaporate — and water vapor's greenhouse push ran away until the surface melted lead. In the 2030s three missions — NASA's DAVINCI and VERITAS, Europe's EnVision — go to reconstruct exactly how it happened.
Related
Figures are representative approximations. Simulated positions use J2000 mean elements.