Mercury: The Closest Planet to the Sun

Mercury is the smallest planet in our solar system, and it is also the closest to the sun. It is a hot, dry, and barren world with a heavily cratered surface. Mercury is a fascinating planet with a long and complex history, and it is still being studied today.

Basic Facts

• Diameter: 4,879 kilometers (3,032 miles)
• Mass: 3.301 × 10^23 kilograms (7.34 × 10^22 pounds)
• Density: 5.427 grams per cubic centimeter (5.427 g/cm^3)
• Gravity: 3.701 meters per second squared (8.2 feet per second squared)
• Orbital period: 87.969 days
• Rotation period: 58.646 days
• Average surface temperature: 167 degrees Celsius (333 degrees Fahrenheit)
• Atmosphere: Very thin, mostly composed of hydrogen and helium

History of Discovery

Mercury was known to ancient astronomers, who called it Hermes, the Greek god of trade and commerce. The first recorded observation of Mercury was by the Babylonians in 2,000 BC.

In the 16th century, the Italian astronomer Galileo Galilei was the first to observe Mercury through a telescope. He discovered that Mercury has phases, just like the moon.

In the 19th century, astronomers began to learn more about Mercury’s surface. They discovered that it is heavily cratered, just like the moon. They also discovered that Mercury has no atmosphere.

In the 20th century, several spacecraft visited Mercury. The first spacecraft to fly by Mercury was Mariner 10 in 1974. Mariner 10 took the first close-up images of Mercury’s surface.

In 2004, the MESSENGER spacecraft became the first spacecraft to orbit Mercury. MESSENGER spent four years orbiting Mercury, taking thousands of images and making many important discoveries about the planet.

In 2018, the BepiColombo spacecraft launched to Mercury. BepiColombo is a joint mission by the European Space Agency (ESA) and the Japan Aerospace Exploration Agency (JAXA). BepiColombo will arrive at Mercury in 2025.

Future Missions

In addition to BepiColombo, there are several other missions planned to Mercury. The European Space Agency is planning a mission called Mercury Planetary Orbiter and Sample Return. This mission will orbit Mercury for two years, collecting samples of the planet’s surface. The samples will then be returned to Earth for analysis.

The United States is also planning a mission to Mercury. This mission, called Mercury Surface, Space Environment, Geochemistry, and Ranging (MESSENGER 2), is scheduled to launch in 2030. MESSENGER 2 will orbit Mercury for three years, studying the planet’s atmosphere, surface, and interior.

Interesting Facts

• Mercury is the only planet in our solar system that has no moons.
• Mercury has the shortest day of any planet in our solar system. A day on Mercury lasts just 58.6 Earth days.
• Mercury has the largest iron core of any planet in our solar system. The core makes up about 75% of the planet’s mass.
• Mercury’s surface is covered in craters, just like the moon. The largest crater on Mercury is Caloris Basin, which is about 1,550 kilometers (960 miles) wide.

Conclusion

Mercury is a fascinating planet with a long and complex history. It is still being studied today, and scientists are learning new things about it all the time.

You may also like:

Mercury: The Closest Planet to the Sun

Venus: The Earth’s Twin or a Very Different Planet?

Mars: Comprehensive Exploration, unveiling the Mysteries

Jupiter: A Cosmic Giant – Symphony of Storms

Saturn: A Gaseous Giant with Enthralling Rings and Diverse Moons

Bibliography

• Binzel, R. P., McSween, H. Y., Rivkin, A. S., et al. (2010). MESSENGER: A Mission to Mercury. Space Science Reviews, 153(1-4), 41-72.
• Hauck, S. A., & Johnson, C. L. (2019). Mercury: Inside the iron planet. Elements: An International Magazine of Mineralogy, Geochemistry, and Petrology, 15(1), 21-26.
• Kivelson, M. G., Khurana, K. K., Russell, C. T., et al. (2004). Magnetic field and internal structure of Mercury. Science, 303(5664), 1957-1962.
• Murray, C. D., & Dermott, S. F. (2001). Solar system dynamics (2nd ed.). Cambridge, MA: Cambridge University Press.
• Weidenschilling, S. J. (1985). The distribution of mass in the solar nebula: Implications for planetary accretion. Icarus, 62(1), 1-36.