Mercury's eccentric orbit takes the small planet as close as 47 million km (29 million miles) and as far as 70 million km (43 million miles) from the sun. If one could stand on the scorching surface of Mercury when it is at its closest point to the sun, the sun would appear more than three times as large as it does when viewed from Earth. Temperatures on Mercury's surface can reach 800 degrees Fahrenheit (430 degrees Celsius). Because the planet has no atmosphere to retain that heat, nighttime temperatures on the surface can drop to -290 degrees Fahrenheit (-180 degrees Celsius).
Solar system Exploration - Mercury - In pictures