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Venus and Earth
The surface-conditions desk
A sourced comparison of Venus and Earth. The table is the NASA fact sheet. The panels walk through those figures, and they say so when NASA Science rounds them differently.
Choose a topic. The comparison table below does not change. It is the same NASA fact-sheet record, seen more clearly, not a different one.
Temperature
The same fact sheet gives the average surface temperature as 737 K (464 °C). [NASA Fact Sheet] Its thick atmosphere traps heat in a runaway greenhouse effect, with surface temperatures hot enough to melt lead — about 872 °F (467 °C), according to NASA Science. [NASA Science] Surface temperatures are hot enough to melt lead. [NASA Science] On NASA’s comparative planetary fact sheet, the mean temperature of Venus is 464 °C, against 15 °C for Earth and 167 °C for Mercury. [NASA Fact Sheet] The fact sheet lists the diurnal temperature range as about zero. [NASA Fact Sheet] NASA Science gives Venus a very slight tilt of only three degrees, too little to produce noticeable seasons. [NASA Science]
The two NASA figures are close, and both are far above Mercury’s mean of 167 °C on the comparative sheet. The desk does not pick a winner; it shows both.
Temperature
The same fact sheet gives the average surface temperature as 737 K (464 °C). [NASA Fact Sheet] Its thick atmosphere traps heat in a runaway greenhouse effect, with surface temperatures hot enough to melt lead — about 872 °F (467 °C), according to NASA Science. [NASA Science] Surface temperatures are hot enough to melt lead. [NASA Science] On NASA’s comparative planetary fact sheet, the mean temperature of Venus is 464 °C, against 15 °C for Earth and 167 °C for Mercury. [NASA Fact Sheet] The fact sheet lists the diurnal temperature range as about zero. [NASA Fact Sheet] NASA Science gives Venus a very slight tilt of only three degrees, too little to produce noticeable seasons. [NASA Science]
The two NASA figures are close, and both are far above Mercury’s mean of 167 °C on the comparative sheet. The desk does not pick a winner; it shows both.
Pressure
The NASA fact sheet gives the surface pressure as 92 bars. [NASA Fact Sheet] NASA Science puts the atmospheric pressure at the surface at about 93 times what it is at sea level on Earth. [NASA Science] The same comparative table lists a surface pressure of 92 bars for Venus and 1 bar for Earth. [NASA Fact Sheet]
Ninety-two bars on the fact sheet, about 93 times sea level on NASA Science: the same crushing idea, recorded two ways.
The air
Near the surface, by volume, the atmosphere is 96.5% carbon dioxide (CO₂) and 3.5% nitrogen (N₂). [NASA Fact Sheet] The atmosphere is mostly carbon dioxide, with dense clouds composed of sulfuric acid. [NASA Science] Its thick atmosphere traps heat in a runaway greenhouse effect, with surface temperatures hot enough to melt lead — about 872 °F (467 °C), according to NASA Science. [NASA Science]
Day and year
Venus orbits the Sun at a semimajor axis of 108.210 million km, with a sidereal orbit period of 224.701 Earth days. [NASA Fact Sheet] The sidereal rotation period is −5,832.6 hours, 243.690 times as long as Earth’s, and the rotation is retrograde. [NASA Fact Sheet] The length of a solar day on Venus, on the fact sheet, is 2,802.0 hours, or 116.750 Earth days. [NASA Fact Sheet] NASA Science gives a sidereal day of 243 Earth days, longer than a Venus year of 225 Earth days. [NASA Science] Venus spins slowly in the opposite direction from most planets, so the Sun would rise in the west and set in the east. [NASA Science]
NASA Science rounds the year to 225 Earth days and the sidereal day to 243. The fact sheet keeps 224.701 and −5,832.6 hours (a ratio of 243.690).
Size and weight
Venus is similar in structure and size to Earth, and is sometimes called Earth’s twin. [NASA Science] The equatorial radius is 6,051.8 km, about 0.949 times Earth’s. [NASA Fact Sheet] Venus has a mass of 4.8673 × 10²⁴ kg, about 0.815 times the mass of Earth. [NASA Fact Sheet] Mean surface gravity is 8.87 m/s², about 0.903 times Earth’s. [NASA Fact Sheet] Escape velocity at Venus is 10.36 km/s. [NASA Fact Sheet]
A missing dynamo
Venus does not have its own internally generated magnetic field. It has a weak induced magnetic field, created by the interaction of the Sun’s magnetic field with the planet’s outer atmosphere. [NASA Science] That table also marks Venus as having no global magnetic field, against “Yes” for Earth. [NASA Fact Sheet]
| Figure | Venus | Earth |
|---|---|---|
| Average surface temperature | 737 K (464 °C) | See the Earth column on the comparative fact sheet: 15 °C |
| Surface pressure | 92 bars | 1 bar |
| Atmosphere, near the surface | 96.5% carbon dioxide, 3.5% nitrogen | — |
| Sidereal orbit period | 224.701 Earth days | 365.256 Earth days |
| Sidereal rotation period | −5,832.6 hours (retrograde) | 23.9345 hours |
| Length of a solar day | 2,802.0 hours (116.750 Earth days) | 24.0000 hours |
| Equatorial radius | 6,051.8 km | 6,378.1 km |
| Mean surface gravity | 8.87 m/s² | 9.82 m/s² |
| Natural satellites | 0 | 1 |
| Planetary rings | None | None |
| Obliquity to the orbit | 177.36° | 23.44° |
The 15 °C Earth temperature is from NASA’s comparative planetary fact sheet, checked on 15 November 2026. NASA Science, on the same date, rounds the Venus surface to about 467 °C and about 93 times sea-level pressure. The desk keeps the fact-sheet numbers in the table so the two sources stay distinct.
Escape velocity at Venus is 10.36 km/s. [NASA Fact Sheet] The Bond albedo is 0.77, about 2.6 times Earth’s. [NASA Fact Sheet]
The desk is our arrangement of published NASA figures, not a new measurement.