On 5 February 1974, Mariner 10 took this first close-up photo of Venus.
Made using an ultraviolet filter in its imaging system, the photo has been colour-enhanced to bring out Venus’s cloudy atmosphere as the human eye would see it. Venus is perpetually blanketed by a thick veil of clouds high in carbon dioxide and its surface temperature approaches 480 degrees Celsius.
Launched on 3 November 1973 atop an Atlas-Centaur rocket, Mariner 10 Atlas-Centaur rocket, Mariner 10 flew by Venus in 1974.
Image credit: Nasa