A year on the planet Mercury is the equivalent of 87.97 Earth days. It orbits the sun approximately four times for every year on Earth.Know More
Mercury is the closest planet to the sun and has a shorter orbit than Earth. It rotates much slower, however, with each day lasting the equivalent to 58.65 Earth days.
The average distance to the sun is about 36 million miles, but this distance varies. Sometimes Mercury gets as close as 28 million miles from the sun while at other times it is 43 million miles away. This means that the orbit speed varies, depending on how close to the sun the planet is. Just before Mercury reaches its maximum orbit speed, that speed and its rotational speed become aligned. This gives the appearance of a static sun. Then, for a period of 8 days, Mercury orbits faster than it rotates. This makes it look as though the sun is going backwards in the sky.
Mercury's year is the shortest of all the planets in the solar system. Earth's is 365 days, while on Mars a year takes 687 Earth days. Neptune has the longest year. It takes more than 164 Earth years to orbit the sun.Learn more about Planets
The planet Mercury completes a single rotation in just under 176 days. Mercury was once thought to be tidally locked, and its rotation was not discovered until 1965.Full Answer >
Mercury has a radius of 2,439.7 kilometers, making it smaller than some moons and the smallest planet in the solar system. Its mass is equal to 0.055 of Earth's.Full Answer >
The planet Mercury does not have a moon. At one time, astronomers from NASA thought the planet Mercury might have a moon, but research proved that theory to be incorrect.Full Answer >
The planet Mercury was first observed by Sumerians, a group of people who lived in Mesopotamia from 3,500 B.C. to 2,000 B.C. Sumerians called the planet Enki.Full Answer >