As far as hospitable places for life go, Venus is far from ideal. A dense atmosphere wraps the planet up in a blanket-like layer of gases that traps heat, making it the hottest planet in the Solar System at over 460 degrees Celsius. The pressure on the surface is over 90 Earth atmospheres, which was enough to crush the Soviet spacecraft Venera 5 and 6 flat when they landed in 1969. Its barren landscape is covered in active volcanoes, and the clouds in its atmosphere are composed of up to 96 per cent sulphuric acid, the same kind of caustic stuff you’d find in a car battery.
An ultraviolet image of Venus’ clouds, taken by NASA’s Pioneer orbiter in 1979
© NASA
But for 60 years this hasn’t stopped scientists from considering it a likely planet to find life in our Solar System, partly because life ekes out an existence in some incredibly hostile places on Earth: the crushing ocean pressures at the bottom of the Mariana Trench, the boiling and acidic waters of the Grand Prismatic Spring and kilometres high in the Earth’s stratosphere. There’s also a thin layer in the Venusian atmosphere where conditions are quite comfortable for life, a safe haven within Venus’ own Goldilocks zone around the Sun.