How large is the moon compared to Earth? The Moon, Earth’s only natural satellite, is about 27% the size of Earth, making it significantly smaller. At COMPARE.EDU.VN, we provide a detailed size comparison of these two celestial bodies, exploring their dimensions and other fascinating facts, offering a clear understanding of their relative sizes and characteristics. Discover more about their planetary data, lunar size, and relative scale.
Table of Contents:
- Understanding the Size Difference Between the Moon and Earth
- Key Lunar and Earth Statistics
- Visualizing the Size Comparison
- Moon Mass, Density, and Gravity
- The Moon’s Gravity Map
- Comparison of Our Moon With Other Moons in the Solar System
- The Phenomenon of Supermoons
- Why Does the Moon Appear Larger Near the Horizon?
- Additional Resources
- Frequently Asked Questions (FAQ)
1. Understanding the Size Difference Between the Moon and Earth
How big is the Moon in comparison to the Earth? The moon’s size relative to Earth is a common question for those curious about space. The moon has a mean radius of 1,079.6 miles (1,737.5 kilometers) and a mean diameter of 2,159.2 miles (3,475 km). According to NASA, the moon is less than a third the width of Earth. Its equatorial circumference is 6,783.5 miles (10,917 km). This size difference significantly impacts various aspects, from gravitational forces to the visibility of the moon in our night sky.
The moon may seem large, but that is because it is the closest celestial body to Earth, averaging about 238,855 miles (384,400 km) away. Understanding the size differences between Earth and its moon is crucial for appreciating the dynamics of our solar system. These aspects influence tides, eclipses, and even the potential for future lunar missions.
2. Key Lunar and Earth Statistics
What are the specific measurements that highlight how the moon compares to Earth? Consider these key lunar statistics:
- Radius: 1,079.6 miles (1,737.5 km)
- Diameter: 2,159.2 miles (3,475 km)
- Surface Area: 14.6 million square miles (38 million square km)
- Mass: 7.35 x 10^22 kg
- Density: 3.34 grams per cubic centimeter (3.34 g/cm3)
In contrast, Earth’s radius is approximately 3,959 miles (6,371 km), and its diameter is about 7,918 miles (12,742 km). Earth’s surface area dwarfs the moon’s, and its mass is about 81 times greater.
| Feature | Moon | Earth |
|---|---|---|
| Radius | 1,079.6 miles (1,737.5 km) | 3,959 miles (6,371 km) |
| Diameter | 2,159.2 miles (3,475 km) | 7,918 miles (12,742 km) |
| Surface Area | 14.6 million square miles | 197 million square miles |
| Mass | 7.35 x 10^22 kg | 5.97 x 10^24 kg |
| Density | 3.34 g/cm3 | 5.51 g/cm3 |
| Volume | 2.1958×1010 km3 | 1.08321×1012 km3 |
| Distance from Earth | Average 238,855 miles | N/A |
| Orbital Period | 27.3 days | 365.25 days |
Understanding these figures can help anyone grasp the true scale of our Moon size relative to the Earth.
3. Visualizing the Size Comparison
How can we better visualize the difference in size between the moon and Earth? One helpful analogy, according to a statement from NASA, is to imagine Earth as the size of a nickel. In this scenario, the moon would be about the size of a coffee bean. This 1:4 ratio makes Earth’s moon stand out compared to other planets and their moons.
The moon’s surface area is about 14.6 million square miles (38 million square km), less than the continent of Asia’s total surface area (17.2 million square miles or 44.5 million square km). Consider visiting COMPARE.EDU.VN for interactive tools that visually compare the sizes of various celestial bodies, including the moon and Earth.
4. Moon Mass, Density, and Gravity
What are the moon’s mass, density, and gravitational force compared to Earth’s? The moon’s mass is 7.35 x 10^22 kg, approximately 1.2% of Earth’s mass, meaning Earth weighs 81 times more than the moon. Its density is 3.34 grams per cubic centimeter (3.34 g/cm3), about 60% of Earth’s density.
The moon’s gravitational force is only about 16.6% of Earth’s gravity. On Earth, a person weighing 100 lbs would weigh only 16.6 lbs on the moon. This lower gravity would allow someone who can jump 10 feet on Earth to jump almost 60 feet on the moon.
5. The Moon’s Gravity Map
How does the moon’s gravity vary across its surface? NASA’s Gravity Recovery and Interior Laboratory (GRAIL) mission mapped the moon’s gravity in unprecedented detail in 2012. According to Maria Zuber, the GRAIL principal investigator at MIT, the moon’s gravity field closely reflects its surface topography. This map allows scientists to correlate changes in gravity with surface features like craters, rilles, and mountains.
Understanding the moon’s gravity is essential for planning lunar missions and exploring the moon’s internal structure. The GRAIL mission provided crucial insights, helping scientists uncover the moon’s hidden secrets.
6. Comparison of Our Moon With Other Moons in the Solar System
How does our moon compare to other moons in the solar system? Our moon is the fifth-largest in the solar system and the largest relative to its planet. Jupiter’s moon, Ganymede, is the largest overall.
Here is a comparison of the 10 biggest moons in the solar system:
| Rank | Moon | Equatorial Radius | Parent Planet |
|---|---|---|---|
| 1 | Ganymede | 1,635 miles (2,631 km) | Jupiter |
| 2 | Titan | 1,600 miles (2,575 km) | Saturn |
| 3 | Callisto | 1,497 miles (2,410.3 km) | Jupiter |
| 4 | Io | 1,131.7 miles (1,821.6 km) | Jupiter |
| 5 | The Moon | 1,079.6 miles (1,737.5 km) | Earth |
| 6 | Europa | 969.84 miles (1,560.8 km) | Jupiter |
| 7 | Triton | 840.96 miles (1,353.4 km) | Neptune |
| 8 | Titania | 490.19 miles (788.9 km) | Uranus |
| 9 | Rhea | 474.91 miles (764.3 km) | Saturn |
| 10 | Oberon | 473.11 miles (761.4 km) | Uranus |
While our moon is smaller than others like Ganymede and Titan, its relative size compared to Earth is unique, influencing Earth’s tides and stability.
7. The Phenomenon of Supermoons
Why does the moon sometimes appear larger in the night sky? The answer lies in the moon’s orbit. The moon’s orbit is not circular, so its distance from Earth varies. When the moon is closest to Earth (approximately 226,000 miles or 363,300 km), it is at perigee.
When a full moon coincides with perigee, it’s called a supermoon. Supermoons appear 14 percent larger and 30 percent brighter than usual. Richard Nolle, an astrologer, first used the term “supermoon” in 1979 to describe a new or full moon within 90 percent of its closest approach to Earth.
The astronomical term for this phenomenon is perigee-syzygy moon. NASA’s Jet Propulsion Laboratory explains that “syzygy” refers to the alignment of three celestial bodies, in this case, the Sun, Moon, and Earth.
8. Why Does the Moon Appear Larger Near the Horizon?
Why does the moon sometimes look particularly big when rising or setting near the horizon? This is an optical illusion. Distant objects on the horizon make the moon seem larger. This illusion, known as the moon illusion or the Ponzo illusion, has been observed since ancient times but lacks a generally accepted explanation.
One theory suggests that our brains are used to seeing clouds a few miles above us. Clouds on the horizon can be tens of miles away. If a cloud on the horizon is the same size as clouds overhead, we know it must be huge. The moon near the horizon appears the same size as it normally does overhead, so our brains add a similar size increase.
Another theory is that the moon seems larger near the horizon because we compare its size to nearby trees and objects on Earth. The moon looms large in comparison. Overhead, amid the vast expanse of outer space, the moon seems diminutive.
9. Additional Resources
Where can you find more information about the moon and space? Educational infographics from ESA provide fast moon facts. The Exploratorium offers a fun interactive activity to see how much you would weigh on other worlds. The Illusion Index from the University of Glasgow has a large collection of illusions to explore the Ponzo illusion.
10. Frequently Asked Questions (FAQ)
-
How much smaller is the moon compared to Earth?
The moon is about 27% the size of Earth.
-
What is the diameter of the moon?
The moon’s diameter is 2,159.2 miles (3,475 km).
-
How does the mass of the moon compare to Earth?
The moon’s mass is about 1.2% of Earth’s mass.
-
Why does the moon appear larger during a supermoon?
During a supermoon, the full moon coincides with the moon’s closest approach to Earth (perigee), making it appear larger and brighter.
-
What causes the moon illusion?
The moon illusion is an optical effect that makes the moon seem bigger when rising behind distant objects on the horizon.
-
What is the surface area of the moon?
The moon’s surface area is approximately 14.6 million square miles (38 million square km).
-
How strong is the moon’s gravity compared to Earth?
The moon’s gravity is about 16.6% of Earth’s gravity.
-
Which is the largest moon in the solar system?
Jupiter’s moon, Ganymede, is the largest in the solar system.
-
What is the average distance between the Earth and the moon?
The average distance is approximately 238,855 miles (384,400 km).
-
What was the GRAIL mission?
NASA’s Gravity Recovery and Interior Laboratory (GRAIL) mission mapped the moon’s gravity in unprecedented detail.
-
How does the volume of the moon compare to the Earth?
The moon has a volume of 2.1958×1010 km3 whereas the Earth has a volume of 1.08321×1012 km3.
-
What is the density of the moon?
The density of the moon is 3.34 grams per cubic centimeter (3.34 g/cm3)
Want to delve deeper into the size comparisons and characteristics of celestial bodies? Visit COMPARE.EDU.VN for more comprehensive analyses and comparisons.
Ready to make informed decisions based on detailed comparisons? Whether you’re comparing products, services, or even celestial bodies, COMPARE.EDU.VN provides the resources you need. Visit us at compare.edu.vn to explore a wide range of comparisons and make the best choice for your needs. Contact us at 333 Comparison Plaza, Choice City, CA 90210, United States, or via Whatsapp at +1 (626) 555-9090.
