10 Interesting Facts about Mercury

Unlike most planets, Interesting facts about Mercury have made the planet possess numerous stand-out features that have attracted our interest. Do you know that Mercury is the second densest planet within the solar system? Other interesting facts about mercury will make you fall in love with the planet. Mercury claims the title of the smallest planet after Pluto was demoted to a dwarf planet.

What’s more? More space agencies are beginning to explore the terrestrial planet because of its unique facts. So what makes Mercury unique? The 10 interesting facts about Mercury consist of the following.

1. Mercury’s Atmosphere Changes with its distance from the sun

Mercury has a thin atmosphere, also referred to as an exosphere. Based on the Scientific research conducted on the planet, it was discovered that Mercury’s thin atmosphere contains sodium, calcium, and magnesium.

Scientists discovered that the concentration of these elements tends to change whenever Mercury moves closer and further distance from the Sun. Scientists also detected that the change in the atmosphere determines the amount of solar radiation that falls on Mercury’s surface.

2. Mercury has ICE

Since the planet’s orbit is so close to the sun, many assume Mercury does not contain any ice cap. But with the data returned so far from the planet, Scientists believed that ice exists inside Mercury’s Craters.

During the formation of the planet billions of years ago, Comets and Meteorites from deep space delivered ice or water vapor to Mercury’s northern and southern poles. But due to the harsh nature of Mercury’s environment, the water vapor remained frozen until this day.

Scientists believed that the existence of ice in this region made the north and south poles to be shadowy and cold. We are still studying the existence of ice on Mercury. But future space missions to the planet will give us a deeper view of the existence of ice on the planet.

3. Mercury may have survived Asteroid Impact

From recent space missions to Mercury, Scientists were able to take a closer look at the planet. Their observation showed that a massive asteroid might have hit Mercury about 4 billion years ago.

The outcome of this collision created a giant crater of about 960 miles (1,545 km) on the planet’s surface. Scientists named this crater Caloris Basin. Comparing the size of this crater to a location on earth, Scientists think that the entire state of Texas can comfortably sit inside it. This estimation has proven the actual size of this massive crater.

Deeper research about the crater revealed that it might be 60 miles or 100 km wide. Future space missions to the planet will give us a deeper insight into the Caloris Basin.

4. Mercury is the most neighboring Planet to the Sun

Numerous Celestial bodies, including planets, moons, and asteroids, orbit around the sun within the solar system. However, Mercury has retained the title of the closest planet to the sun.

The planet is so close that the average distance from the Sun to Mercury is about 58 million Km (36 million miles). This implies that the astronomical unit between the planet and the sun is estimated at 0.4 AU.

Because of the distance between these celestial bodies, it takes sunlight about 3.2 minutes to reach Mercury’s surface.

5. Mercury is the fastest planet to orbit the Sun

Mercury revolves around the planet at the speed of 47 kilometers (29 miles) per second. With this speed limit, the planet has remained the fastest planet to orbit the sun.

Remember that Mercury completes one full revolution around the sun in only 88 days. The planet has only accomplished this milestone because of its ability to revolve at the fastest speed around the sun.

6. Mercury has a unique Orbit

Mercury has the potential to travel around the sun’s orbit at 180,000 km/h (112,000 mph). With this rotating speed, the planet orbits the sun, maintaining an elliptical orbit. Mercury often orbits at its closest orbit to the sun at a distance of 29 million miles (47 million km).

It moves around the sun at its furthest distance of 43 million miles (70 million km). Since its rotation around the sun is elliptical, Mercury’s orbit around the sun does not maintain a perfect circle.

7. Mercury is the second Hottest Planet in the solar system

Mercury is the closest planet to the sun. But do you know that Mercury is not the hottest planet? For billions of years, Venus has maintained the position of the hottest planet in the solar system.

The side of Mercury that faces the sun has a temperature of nearly 427 degrees celsius. However, the other side facing away from the sun has a cold temperature of -173 degrees celsius.

8. Mercury is the most cratered planet in the solar system

Several asteroids and comets collided to form planets. However, most planets within the solar system healed from this collision with time. Mercury never followed the footprint of other planets.

Instead of healing and becoming better like most planets, mercury inherited many craters across its surface. Keep in mind that most of these craters are small in size.

However, a few bigger craters still exist on Mercury’s surface. The most prominent crater on Mercury is known as the Caloris Basin. This crater has a diameter of 963 miles, occupying a more significant portion of the planet.

9. Mercury is too difficult to spot in Earth’s night sky: Another Great Interesting Facts about Mercury

Since mercury is the smallest planet in the solar system, you may be struggling to notice the planet over the earth’s night sky. Aside from its small size, Mercury is close to the sun.

The planet rising and setting time is closer to that of the sun. So, people may find it challenging to spot Mercury over the night sky.

10. Only two spacecraft have made it to Mercury, but one is on its way

Unlike other planets in the solar system, space agencies often experience several challenges in visiting mercury. During Mariner 10 mission in 1974 and 1975, the spacecraft flew by Mercury about three times.

NASA could map half of the planet’s surface from this space mission.

This is the first time in history that any space agency can send a manmade object to mercury. After this space mission, no other spacecraft made it to mercury. But in the 21st century, space agencies developed a greater interest in exploring Mercury.

On August 3rd, 2004, NASA launched the messenger probe to study Mercury. The spacecraft successfully entered the orbit of mercury on March 18th, 2011, and began to explore the planet. The space probe completed its space mission in 2012.

What’s more? In 2018, the BepiColombo mission was launched to Mercury. The spacecraft is expected to enter mercury’s orbit in December 2025 and complete its mission in 2027 or 2028.

Other Interesting Facts About Mercury

Aside from the facts listed above, Mercury has other interesting facts that make it unique and attractive to us. Many space agencies are working towards unveiling more mysteries about the planet. these future missions will undoubtedly improve our understanding of the closest planet to the Sun.


Mercury is indeed a planet with a difference. It has numerous outstanding facts that will increase your interest in learning more about the planet. The super interesting facts about Mercury listed above should increase your knowledge about the planet. Which of these above-listed facts caught your interest the most?

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