A guide to the planets: Venus

Venus is a hellish world where surface temperatures are hot enough to melt lead and the clouds are made of acid

The planet Venus taken by Mariner 10

What is Venus like?

In many ways, Venus and Earth are very similar. They are almost identical in size and mass and are relatively close in their distance from the Sun.


But in reality, the worlds could not be more different.

Venus is shrouded from view by thick clouds of sulphuric acid, which float in an atmosphere so thick the surface pressure is 92 times what it is on Earth – about the same as 1km underwater.

Temperatures are hot enough to melt lead as the planet is in the grip of a runaway greenhouse effect.

Venus was once highly volcanic, and this pumped out vast amounts of carbon dioxide.

On Earth, plate tectonics recycle the carbon from eruptions back into the rock, but Venus doesn’t have any tectonics.

Instead, carbon dioxide levels rose until it made up 95 per cent of the atmosphere. This acts like an insulating blanket, trapping the Sun’s heat.

As the temperature rose, what water there was on Venus evaporated, forming a thick layer of swirling cloud that trapped even more heat, contributing to the creation of the planet’s inhospitable conditions.

The view of Venus below the clouds
Using data from multiple radar readings, scientists were able to create this map of what Venus looks like underneath the clouds.

Venus facts

  • Diameter: 12,104km (0.95 times Earth)
  • Mass: 4870 billion trillion kg (0.81 times Earth)
  • Distance from the Sun: 108 million km (0.72 AU)
  • Length of day: 117 days
  • Length of year: 225 days
  • Number of moons: 0
  • Average temperature: 464ºC
  • No of spacecraft visitors: 24
  • Type of planet: Rocky

From where does Venus get its name?

Venus is named after the Roman goddess of love, known as Aphrodite in the Greek pantheon.

It’s thought Venus earned its name from its intense brightness – the goddess was well known for her radiant beauty.

How can I see Venus in the night sky?

Venus is the brightest planet in the sky, outshining everything except the Sun and Moon.

However, as it is an interior planet (closer to the Sun than Earth), it’s only visible for a short window of time around dawn and dusk.

Though Venus can be visible during the day, we strongly recommend you only look for it when the Sun is below the horizon, to stop you accidentally looking directly at the Sun and damaging your eyesight.

The planet is bright enough to be seen with the naked eye, but if you look through a telescope or binoculars you should be able to see that only part of the planet is illuminated.

Venera 13 image of Venus's surface
In 1982, the Soviet probe Venera 13 took the first ever colour photos from the surface of Venus.
Soviet Planetary Exploration Program, NSSDC

How have we explored Venus?

Venus is one of the most visited planets in the Solar System thanks to the Soviet Union’s Venera and Vega programmes that ran from 1966 to 1984.This was an astonishing series of 18 spacecraft that viewed the planet from orbit, dropped onto its surface, and even floated through the atmosphere on the bottom of a 3.5 m wide balloon.

The intense heat, pressure and caustic atmosphere meant none of the probes lasted much more than an hour on the surface.

Due to the difficulties in landing, all other missions to Venus have been orbiters.


Explored by: The Mariner programme (1962–67, NASA); the Venera programme (1966–86, Soviet); Pioneer Venus (1978); Vega (1983; Soviet); Magellan (1990, NASA); Venus Express (2006, ESA); Akatsuki (2015, JAXA)