Exploring Mercury: The Smallest Planet in the Solar System

Mercury, the closest planet to the sun, is the smallest in the solar system with a diameter of 4879 km. Despite its size, it is denser than Earth due to its rocky and metallic composition. Mercury has no moons and an orbit period of 88 days. Its surface is marked by craters from asteroid impacts. Discovered by Assyrian astronomers, it is visible to the naked eye. Only two spacecraft, Mariner 10 and Messenger, have visited Mercury due to its proximity to the sun, making travel challenging.

Which planet is the closest to the sun and has no moons?

• Mercury

• Venus

• Jupiter

• Mars

Who were the first to discover Mercury?

• Roman astronomers

• Greek astronomers

• Egyptian astronomers

• Assyrian astronomers

Why is Mercury denser than Earth?

• It is closer to the sun

• It has a larger size

• It is composed mainly of rock and metal

• It has more moons

What is the primary reason Mercury is difficult to visit?

• Its high temperature

• Its small size

• Its proximity to the sun

• Its dense atmosphere

Which spacecraft was the first to fly by Mercury?

• Voyager 1

• Mariner 10

• Messenger

• Pioneer 10