article_snippet: It is the second closest planet to the sun at a distance of about 67 million miles (108 million kilometres), and takes about 225 days to orbit the sun.
article_snippet: the planet's extreme high temperatures of almost 480°C (900°F) make it seem an unlikely place for for life as we know it.
article_snippet: An illustration of Nasa's Mariner 10 spacecraft is shown here.
article_snippet: When viewed in visible light, the whole planet simply appears bright yellow or white - as the high amounts of carbon dioxide in the atmosphere reflect a lot of sunlight.