Planets closest to the sun
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Inner Planets Closest to the Sun: Mercury, Venus, Earth, and Mars
The four planets closest to the Sun are Mercury, Venus, Earth, and Mars. These are often called the "inner planets" or "terrestrial planets" because they are rocky and share many similarities in their structure and composition. Their proximity to the Sun distinguishes them from the outer, gas giant planets of the solar system.
Mercury and Venus: The Two Nearest Planets to the Sun
Mercury is the closest planet to the Sun, followed by Venus. Observing these planets can be challenging due to their brightness and position in the sky, but they have played a key role in helping scientists understand planetary orbits and the fundamentals of our solar system.
The Terrestrial Planets: Shared Characteristics
Mercury, Venus, Earth, and Mars are grouped together because they are all rocky planets with solid surfaces. This makes them different from the gas giants further from the Sun. The Moon is sometimes included in this group due to its similarities with these planets.
Solar System Structure: Position of the Inner Planets
The inner planets are located within 0.39 to 1.52 astronomical units (AU) from the Sun, with Mercury at 0.39 AU, Venus at 0.72 AU, Earth at 1 AU, and Mars at 1.52 AU. This region is distinct from the outer solar system, which contains the gas giants and icy bodies.
Conclusion
The planets closest to the Sun—Mercury, Venus, Earth, and Mars—are known as the inner or terrestrial planets. They are characterized by their rocky surfaces and are grouped together due to their similar properties and proximity to the Sun127.
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