4. Venus, Earth's Twin

The team explores our nearest neighbour Venus, discovering how it formed and how ESA's Venus Express spacecraft has revealed the secrets of its atmosphere. -- How can two such similar planets have become so different? One is the crucible of life, the other an inferno with a surface scorched by raining acid, yet both began as almost identical bodies. With Venus prominent in the sky in May, the team explores our nearest neighbour, discovering how it formed and how ESA's Venus Express spacecraft has revealed the secrets of its atmosphere.