Mercury is the smallest planet in our solar system and is also the closest planet to the sun. It is only about a third the size of Earth and has a very thin atmosphere. Because it is so close to the sun, Mercury experiences extreme temperatures. During the day it can reach 430 degrees Celsius (800 degrees Fahrenheit), but at night it can plunge to -180 degrees Celsius (-290 degrees Fahrenheit). Mercury also has the longest day of any planet in our solar system. One day on Mercury lasts for 176 Earth days!
Mercury is the closest planet to the sun. The distance from the Sun ranges from 46,000,000 to 70,000,000 km (29,000,000 to 43,000,000 mi).
One year on Mercury lasts for 88 Earth days.
One day on Mercury lasts for 176 Earth days.
Mercury is the only planet in our solar system that has no moons!