Which Planet Is Closest To The Sun

The Closest Planet to the Sun

Have you ever wondered which planet in our solar system is closest to the Sun? The answer may surprise you! Mercury, the smallest and fastest planet in our solar system, holds the title of being the closest planet to the Sun. In this article, we will delve into the fascinating world of Mercury and explore what makes it unique among the other planets.

Mercury: The Smallest and Swiftest

Mercury is the smallest planet in our solar system, measuring only about one-third the size of Earth. Its small size contributes to its swift orbit around the Sun, making it the fastest planet in our solar system. A year on Mercury lasts only 88 Earth days, as it zooms around the Sun at an average speed of 107,082 miles per hour.

Which Planet Is Closest To The Sun

Close Proximity to the Sun

Due to its close proximity to the Sun, Mercury experiences extreme temperatures. During the day, temperatures can soar up to a scorching 800 degrees Fahrenheit, hot enough to melt lead. However, because Mercury has almost no atmosphere to trap heat, nighttime temperatures can plummet to a frigid -290 degrees Fahrenheit.

Mercury’s Unique Orbit

Mercury’s orbit is unlike any other planet in our solar system. It has an elliptical orbit, meaning that its distance from the Sun varies throughout its journey. At its closest point, called perihelion, Mercury is only 28.5 million miles away from the Sun. At its farthest point, called aphelion, it is 43.4 million miles away. This varying distance from the Sun contributes to the extreme temperatures on Mercury.

Surface Features of Mercury

Mercury’s surface is covered with numerous craters, similar to the Moon. These craters were formed by impacts from asteroids and comets over billions of years. In addition to craters, Mercury also has ridges and cliffs, known as scarps, that were created as the planet’s surface cooled and contracted.

Mercury’s Lack of Atmosphere

Unlike Earth, Mercury has a very thin atmosphere composed mostly of oxygen, sodium, hydrogen, helium, and potassium. This thin atmosphere does little to regulate temperature or protect the planet from the Sun’s intense radiation. As a result, Mercury’s surface is constantly bombarded with solar winds and cosmic rays.

Mercury’s Mysteries

Despite being the closest planet to the Sun, Mercury still holds many mysteries for scientists. One of the most intriguing mysteries is the presence of water ice in Mercury’s polar regions. Scientists believe that water ice may exist in permanently shadowed craters where temperatures are cold enough to sustain ice. Future missions to Mercury may provide more insight into this enigmatic discovery.


Mercury, the closest planet to the Sun, offers a unique and fascinating glimpse into the extremes of our solar system. From its blistering temperatures to its mysterious water ice deposits, Mercury continues to captivate scientists and astronomers alike. As we continue to study this small and swift planet, we are sure to uncover more secrets and unlock the mysteries of our solar system.