Mercury vs Moon: Comparison, Size, Mass, Gravity, Similarities and Differences

Mercury vs Moon: Comparison, Size, Mass, Gravity, Similarities and Differences

Mercury vs Moon

As we cast our eyes upon the celestial canvas above, the radiant Mercury and the serene Moon often command our attention. These two fascinating objects, though vastly different in nature, contribute to the cosmic symphony that unfolds beyond our planet. This blog post embarks on an exploration of the intriguing disparities between Mercury and the Moon, unraveling their individual attributes, roles, and significance in our understanding of the universe.

Mercury Compared to Moon

Mercury and the Moon are both celestial bodies within our solar system, but they differ significantly in terms of composition, size, and other key characteristics. Let's delve into their similarities and differences.

Mercury and Moon Similarities

While Mercury and the Moon are distinct in many ways, they share some similarities. Both are rocky bodies, often referred to as terrestrial planets or terrestrial bodies. This means they have solid surfaces composed of rocks and metals, unlike gas giants such as Jupiter or Saturn. Additionally, both Mercury and the Moon lack atmospheres or have extremely thin atmospheres, making their surfaces directly exposed to the harsh conditions of space.

Mercury and Moon Differences

  1. Orbital Characteristics:
    • Mercury: It is an innermost planet and orbits the Sun, completing one orbit roughly every 88 Earth days.
    • Moon: Earth's natural satellite, it orbits our planet with an orbital period of approximately 27.3 days.
  2. Surface Conditions:
    • Mercury: The surface of Mercury is heavily cratered and has extensive plains. It experiences extreme temperature variations, with scorching temperatures on the side facing the Sun and freezing temperatures on the dark side.
    • Moon: Similar to Mercury, the Moon's surface is marked by impact craters, but it also has large plains called maria formed by ancient volcanic activity.
  3. Atmosphere:
    • Mercury: Virtually no atmosphere, resulting in drastic temperature fluctuations between day and night.
    • Moon: Extremely thin exosphere, practically negligible, providing no significant atmospheric protection.
  4. Rotation:
    • Mercury: Has a slow rotation, completing three rotations for every two orbits around the Sun.
    • Moon: Synchronous rotation, meaning it always shows the same face to Earth.

Mercury and Moon Size Comparison

  • Mercury: Mercury is larger than the Moon, with a diameter of approximately 4,880 kilometers (3,032 miles).
  • Moon: The Moon has a diameter of about 3,474 kilometers (2,159 miles), making it significantly smaller than Mercury.

Mercury and Moon Mass Comparison

  • Mercury: It has a higher mass compared to the Moon, with a mass of about 0.055 times that of Earth.
  • Moon: The Moon has a lower mass than Mercury, approximately 0.012 times the mass of Earth.

Mercury and Moon Gravity Comparison

  • Mercury: Mercury has a stronger gravitational pull than the Moon, with a surface gravity about 0.38 times that of Earth.
  • Moon: The Moon has a weaker gravitational force, with a surface gravity of approximately 0.17 times that of Earth.

Mercury and Moon Side by Side

When placed side by side, Mercury would appear larger than the Moon due to its greater diameter. The two bodies would exhibit contrasting surface features, with Mercury displaying a mix of cratered regions and plains, while the Moon showcases its unique combination of craters and maria. Despite their differences, both Mercury and the Moon contribute valuable insights into the geological history and evolution of our solar system.

Mercury and Moon

Here's a concise breakdown of the main differences between Mercury and the Moon:


  • A planet, closest to the Sun.
  • Rocky surface with craters, cliffs, and plains.
  • Smallest planet in the solar system.
  • Eccentric orbit with extreme temperature shifts.
  • Negligible atmosphere (exosphere).
  • Unique iron-rich core and magnetic field.
  • Explored by the Messenger spacecraft.
  • About 4,880 kilometers in diameter.


  • Earth's natural satellite.
  • Impact craters, maria (plains), and highlands on its surface.
  • Larger than Mercury.
  • Revolves around Earth in about 27.3 days.
  • Virtually no atmosphere.
  • Gravitational effects create Earth's tides.
  • Explored by Apollo missions and other missions.
  • About 3,474 kilometers in diameter.

These differences highlight the distinctions between Mercury and the Moon, showcasing their roles, characteristics, and significance within our solar system.

Mercury vs Moon Size

Mercury, the closest planet to the Sun, is relatively small with a diameter of about 4,880 kilometers (3,032 miles). It's the smallest planet in our solar system, and its compact size contributes to its unique characteristics. In contrast, the Moon is larger in diameter, measuring approximately 3,474 kilometers (2,159 miles). While both Mercury and the Moon are significantly smaller than Earth, the Moon's relatively larger size allows it to exert gravitational effects on our planet, contributing to the tides.

Mercury vs Moon Temperature

Mercury experiences extreme temperature fluctuations due to its proximity to the Sun and its thin atmosphere. During its scorching daytime, temperatures can soar to around 800 degrees Fahrenheit (427 degrees Celsius), while its nighttime temperatures plummet to about -290 degrees Fahrenheit (-179 degrees Celsius). The Moon, devoid of a substantial atmosphere, also undergoes dramatic temperature shifts. Lunar daytime temperatures can reach approximately 260 degrees Fahrenheit (127 degrees Celsius), and lunar nights can bring frigid temperatures as low as -280 degrees Fahrenheit (-173 degrees Celsius).

Mercury vs Moon Mass

In terms of mass, Mercury has a higher mass compared to the Moon. Mercury's mass is approximately 3.285 x 10^23 kilograms, making it much more massive than the Moon. The Moon's mass, by comparison, is approximately 7.347 x 10^22 kilograms. The difference in mass contributes to the gravitational effects of each celestial body on surrounding objects, including Earth's tides.

Mercury vs Moon Atmosphere Comparison

Mercury possesses a thin and tenuous exosphere, which consists of atoms and ions that have escaped from its surface. This exosphere is virtually nonexistent compared to the Earth's dense atmosphere. As a result, Mercury's exosphere is unable to retain heat effectively, contributing to its extreme temperature variations. The Moon, however, lacks a substantial atmosphere altogether. Its exosphere is exceptionally thin, comprised mainly of elements like hydrogen, helium, and neon. This lack of atmosphere exposes the Moon's surface directly to the harsh conditions of space.

Moon vs Mercury

Here's a detailed specification table comparing Mercury and the Moon:

Specification Mercury Moon
Classification Planet Natural Satellite (Moon)
Diameter Approximately 4,880 kilometers (3,032 miles) Approximately 3,474 kilometers (2,159 miles)
Distance from Sun Varies due to its elliptical orbit Approximately 238,855 miles (384,400 kilometers)
Surface Composition Rocky terrain with craters, cliffs, and plains Impact craters, lunar maria, highlands
Gravitational Influence Stronger than Moon due to its larger mass Significant gravitational effects on Earth
Orbital Period About 88 Earth days About 27.3 Earth days
Eccentricity of Orbit High eccentricity, resulting in temperature shifts Nearly circular orbit around Earth
Atmosphere Negligible exosphere of atoms and ions Virtually no atmosphere (exosphere)
Temperature Variation Extreme temperature fluctuations due to thin atmosphere Dramatic temperature shifts between lunar day and night
Core and Magnetic Field Iron-rich core with stronger magnetic field No significant magnetic field
Geological Features Craters, cliffs, and plains Impact craters, maria, rugged highlands
Notable Missions Explored by the Messenger spacecraft

Explored by various lunar missions, including the Apollo program

Physical Characteristics

Mercury, the closest planet to the Sun, boasts a rocky surface resembling Earth's. With a diameter of approximately 4,880 kilometers (3,032 miles), it's the smallest planet in our solar system. Its surface is adorned with craters, cliffs, and vast plains. Interestingly, Mercury's iron-rich core sets it apart, giving it a stronger magnetic field than the Moon.

On the other hand, our Moon, Earth's celestial companion, is larger than Mercury, with a diameter of about 3,474 kilometers (2,159 miles). Its surface is an artistic tapestry of impact craters, lunar maria (basaltic plains), and rugged highlands. The Moon's geological history is inscribed upon its surface, a testament to eons of cosmic interactions.

Orbital Dynamics

Mercury, residing in the scorching embrace of the Sun, completes an orbit in about 88 Earth days. Its orbit is known for its eccentricity, resulting in extreme temperature fluctuations between its blistering day and icy night. In contrast, the Moon, our loyal companion, revolves around Earth in approximately 27.3 Earth days. Its gravitational pull leads to the rhythmic rise and fall of Earth's tides.

Atmospheric Disparity

Mercury boasts a negligible atmosphere—a thin exosphere composed of atoms and ions. This tenuous atmosphere is unable to retain heat, contributing to Mercury's extreme temperature shifts. The Moon, however, lacks a substantial atmosphere altogether. Its exosphere is exceptionally thin, allowing its surface to be directly exposed to the harshness of space.

Impact of Exploration

Humanity's quest for knowledge has led to remarkable revelations about both Mercury and the Moon. NASA's Messenger spacecraft provided a detailed look at Mercury's surface, revealing complex geological formations and even evidence of ice in shadowed craters. Meanwhile, the Moon has been the subject of numerous exploratory missions, including the iconic Apollo program that brought astronauts to its surface. These missions unveiled the Moon's history, geology, and potential resources.

Future Insights and Exploration

While the contrasts between Mercury and the Moon continue to captivate our imaginations, the allure of exploration holds the promise of unveiling even more about these intriguing worlds.

NASA's upcoming BepiColombo mission is set to provide further insights into Mercury's mysteries. This joint mission with the European Space Agency will send a spacecraft to orbit the planet, studying its composition, magnetic field, and surface features in unprecedented detail. This mission is poised to rewrite our understanding of this enigmatic world.

Meanwhile, as humanity eyes the Moon once again, the Artemis program aims to return astronauts to its surface by the mid-2020s. With an emphasis on sustainable lunar exploration, this endeavor will expand our understanding of the Moon's resources, geology, and potential as a stepping stone for further space exploration.

Final Thoughts

As we marvel at Mercury and the Moon, we recognize the profound diversity that characterizes our solar system. Mercury, with its mysterious core and extreme temperature variations, reminds us of the Sun's relentless influence. The Moon, a silent witness to Earth's history, plays a vital role in our tides and seasons. These celestial companions, though distinct, weave together the intricate fabric of our cosmic story, inviting us to continue our exploration and discovery of the universe's secrets.

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