Mercury

Mercury. . , This tiny sphere is the planet Mercury at one 10-billionth actual size. , , If Mercury were this big, how far away would the sun and other planets be? Look at the map on the lower panel to find your position in the solar system.. , , Bottom section of the marker , Voyage to Mercury , The Smallest planet and the closest to the Sun, Mercury is a world of extremes. Dawn brings 3 months of continuous sunshine, scorching the equator with temperatures soaring to 840°F (450°C), as hot as glowing coals. Sunset brings 3 months of frigid darkness. Temperatures plummet to -290­­°F (-180°C), far colder than anywhere on Earth. , , A Dead World , Mercury has no active volcanoes, no mountains pushing upward, no perceptible atmosphere, no life. Craters cover the surface. Most are scars from the dawn of the solar system, when asteroids and comets pounded the planet. Now, all is still and silent. , , An Airless World , Mercury has no air to scatter sunlight and color its sky. Even in daylight if you face away from the blazing Sun, the sky appears black and dotted with stars. Sometimes visible among them are a blue speck and its tiny companion--Earth and its Moon. , , Walk to Venus about 8 steps , , Imagine , The Sun moves so slowly across Mercury's sky that if you leisurely walked forever westward you would never see it set. , , Walk to Sun about 9 steps , , In the real solar system, the planets never line up as they orbit the Sun..