Size of mars compared to earth
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Size of Mars Compared to Earth
Mars Diameter and Surface Area
Mars, often referred to as the "Red Planet," is significantly smaller than Earth. Mars has an average diameter of 6,792 kilometers, which places it between the size of Earth and the Moon, making it the seventh smallest planet in our Solar System 1. In terms of surface area, Mars covers approximately 144,798,500 square kilometers, which is about 28% of Earth's surface area. This is roughly equivalent to the total area of dry land on Earth 1.
Mars' Mass and Density
Mars is also less dense than Earth and has about half the radius of our planet. Consequently, Mars has only about one-tenth of Earth's mass. This lower mass results in a surface gravity on Mars that is approximately 40% of Earth's gravity 4. This significant difference in mass and gravity is a key factor in the distinct environmental and geological characteristics observed on Mars.
Orbital Characteristics and Day Length
Mars orbits the Sun at an average distance of approximately 230 million kilometers, which is about 1.5 astronomical units (AU) from the Sun. It takes Mars 687 Earth days to complete one orbit around the Sun. Additionally, a solar day on Mars, known as a "sol," is about 40 minutes longer than an Earth day 4.
Formation and Size Discrepancy
The smaller size of Mars compared to Earth and Venus has been a longstanding puzzle in planetary formation theories. Recent models, such as the Viscously Stirred Pebble Accretion (VSPA), provide an explanation for this size discrepancy. According to this model, Mars' growth was stunted due to the inefficiency of pebble accretion beyond approximately 1.5 AU from the Sun. This model also accounts for the low mass of the asteroid belt, suggesting a unified explanation for the structure of the inner Solar System 3.
Conclusion
In summary, Mars is significantly smaller than Earth in terms of diameter, surface area, and mass. Its unique formation process and orbital characteristics contribute to its distinct size and environmental features. Understanding these differences helps scientists gain deeper insights into the formation and evolution of terrestrial planets in our Solar System.
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