Venus is the planet closest to Earth in size, smothered in a crushing carbon dioxide atmosphere and acid clouds that make its surface the hottest of any planet.
At a glance
| radius | 6,050 km (0.95 × Earth) |
|---|---|
| distance from the Sun | 0.723 AU (108 million km) |
| sunlight takes | 6.02 minutes |
| one orbit | 225 days |
| orbit eccentricity | 0.0068 |
| reflects | 69% of the sunlight it gets |
Read off the piece’s own catalogue, the same values it draws with.
About Venus
Venus is built much like Earth, rock around an iron core, and almost as large. Its atmosphere is what sets it apart: an enormously thick blanket of carbon dioxide, with a surface pressure like that deep under the ocean on Earth. The runaway greenhouse effect it creates keeps the ground hotter than Mercury’s sunlit side, though Venus is farther from the Sun, and hot enough to melt lead.
A permanent deck of sulphuric acid cloud hides the surface from view. What we know of the ground comes from radar, above all from the Magellan orbiter, which mapped volcanoes and lava plains across the planet, and from the Soviet Venera landers, which survived on the surface only briefly before the heat overcame them. Venus also turns very slowly and backwards compared with most planets, so slowly that its day is longer than its year.
Those bright clouds reflect most of the sunlight that reaches them, which is why Venus is the brightest object in the night sky after the Moon, the morning and evening star. Through a telescope it shows phases like the Moon, one of the observations that showed the planets go round the Sun.
What you see in the piece
In visible light Venus is a blank, bright cloud deck, lit only by the sunlight it reflects; the surface beneath is never seen. Like every planet, it vanishes completely when you look back from another star.
Questions
Why is Venus so bright?
Its clouds of sulphuric acid reflect 69% of the sunlight it gets, and it comes closer to Earth than any other planet, so it outshines everything in the night sky except the Moon.
Why is Venus hotter than Mercury?
Its thick carbon dioxide atmosphere traps heat in a runaway greenhouse effect, so its surface stays hotter than anywhere on Mercury, day or night, even though Mercury is closer to the Sun.