Mercury is the closest planet to the Sun and the smallest. It is a rocky planet like Venus, Earth, and Mars. It is named after the Roman god of commerce due to its speed. After Earth, Mercury is the second densest planet.
Mercury is the closest planet to the Sun. The planet is named after the Roman god of commerce, who was known for being very swift. Mercury does not have an atmosphere, so it doesn’t retain the heat from the Sun. Temperatures can range from 430°C (800°F) during the day and -180°C (-290°F) during the night. Mercury moves faster than any other planet, moving at 50 km per second as it orbits the Sun. It is the smallest planet and is only a little bit larger than Earth’s moon. Like Venus, Earth, and Mars, Mercury is a rocky planet.
Mercury has been difficult to study because of its proximity to the Sun. The first spacecraft to visit mercury was Mariner 10. When it visited, it managed to take pictures of about 45% of Mercury’s surface. The next time Mercury was visited by a spacecraft was by the Messenger mission. The mission was launched in 2004 and reached Mercury in 2011. The mission mapped 100% of Mercury’s surface and crashed into the surface of Mercury in April 2015.
The surface of Mercury looks similar to our moon, with lots of large craters from impacts from rocks falling from space.