Planet Mug MERCURY

MERCURY (Shown in true color) is the closest planet to the sun and the smallest planet in our solar system. The tiny planet has no moon of its own and zips around the sun faster than all the other planets Its orbit around the Sun takes 88 Earth days, which is why the Romans named it after their swift-footed messenger god. (Mercury rotates slowly. One rotation takes nearly 59 Earth days to complete) Mercury is the second densest planet after Earth, with a huge metallic core roughly 2,200 to 2,400 miles (3,600 to 3,800 kilometers) wide, or about 75% of the planet's diameter. In comparison, Mercury's outer shell is only 300 to 400 miles (500 to 600 km) thick. The combination of its massive core and composition, which includes an abundance of volatile elements, has left scientists puzzled for years. Because the planet is so close to the sun, Mercury's surface temperature can reach a scorching 840 degrees Fahrenheit (450 degrees Celsius). However, since this world doesn't have much of a real atmosphere to entrap any heat, at night temperatures can plummet to minus 275 degrees Fahrenheit (minus degrees 170 Celsius), a temperature swing of more than 1,100 degrees Fahrenheit (600 degrees Celsius), the greatest in the solar system.