Venus's hostile atmosphere

Katrin Raynor takes a look at a planet where the skies boil and the clouds rain acid

- Katrin Raynor

Christiaan Huygens, a Dutch astronomer, first hypothesised the existence of Venus's atmosphere in 1698 when he observed the planet through his telescope. Despite viewing its waxing and waning phases, he could not see any features on its surface and guessed that a thick atmosphere must be obscuring his view. Years later in 1761, Russian Mikhail V Lomonosov detected the refraction of solar rays while observing the transit of Venus across the Sun - and thus discovered the atmosphere of Venus.

In 1962, Venus became the first planet to be visited by spacecraft, when NASA's Mariner 2 flew within 34,854km of the planet. Since then, nearly 40 missions have visited Venus and this month marks the 45th anniversary of NASA's Pioneer Venus mission and the Soviet Venera 11 and 12, all of which collected data about the planet's hostile atmosphere.

Venus is the second planet from the Sun and our nearest planetary neighbour. It has a rocky body similar in nature to Mercury, Earth and Mars. Named after the goddess of love and beauty, and described as Earth's twin, Venus is only 638.4km smaller in diameter than Earth and has a similar mass.