Venus: Earth's evil twin

Artist's impression of Venus Express in orbit. (Photo: ESA/AP) Photograph: AP

Artist's impression of the solar system with the Sun (left), and Mercury, Venus, the Earth (from left in the foreground), Uranus, Neptune, Saturn, Jupiter and Mars (from left in the background). Image: AP/ESA/HO Photograph: Anon/AP

Artist's impression of Venus Express in orbit around the planet. The probe was launched in November 2005. (Image: ESA/PA) Photograph: Anon/AP

Ultraviolet image captured by Venus Express at the planet's southern hemisphere. (Photo: ESA/PA) Photograph: Express/PA

Three-dimensional image of the "south polar vortex", a vast swirl of clouds the size of Europe. Similar features have been found at the planet's north pole. Conditions in the southern polar region change dramatically, perhaps as a result of sulphur dioxide gas bubbling up from below. (Photo: ESA/PA) Photograph: PA

Image showing the fluorescence emission of carbon dioxide from the upper atmosphere on the day side of the planet. (Photo: ESA/PA) Photograph: Express/PA

Artist's impression of lightning at the planet's surface. An instrument on the Venus Express that detects particular electromagnetic frequencies has observed the telltale signature of lightning. (Image: ESA/AP) Photograph: Anon/PA

Artist's impression of lightning at the planet's surface (Image: ESA/AP) Photograph: Anon/PA