Solar System Overview: Planets and Structure

The Planets of Our Solar System

A tour of the eight planets and the structure of our celestial home

• Formation and Structure of the Solar System
• The Inner Solar System (Terrestrial Planets)
• The Outer Solar System (Gas and Ice Giants)
• Dwarf Planets and Small Bodies
• The Sun and Heliosphere

• Formed approximately 4.6 billion years ago from a collapsing molecular cloud.
• The Sun contains 99.86% of the system's total mass.
• Dominated by eight major planets.
• Characterized by a temperature gradient decreasing from the Sun outward.
• Bound by gravity and permeated by the solar wind.

1

Inner Solar System

The Terrestrial Planets

Mercury & Venus Mercury: Closest to the Sun, no significant atmosphere. Venus: Thick, toxic atmosphere, extreme greenhouse effect, hottest planet.

Earth & Mars Earth: The only known planet with life, abundant liquid water. Mars: The "Red Planet", hosts evidence of past water, potential for habitability.

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Outer Solar System

Gas Giants and Ice Giants

Gas Giants Jupiter: Largest planet, massive storm systems, many moons. Saturn: Iconic ring system, low density, complex satellite family.

Ice Giants Uranus: Tilted on its side, cold, blue-green methane atmosphere. Neptune: Distant, windy, cold, dynamic weather patterns.

• 90%: Mass Share
• 5 AU: Frost Line

• Objects that orbit the Sun but do not dominate their orbits.
• Includes Ceres (in the asteroid belt), Pluto, Eris, Makemake, and Haumea.
• Often located in the Kuiper belt or scattered disc.
• Smaller bodies like asteroids, comets, and meteoroids also populate these regions.

The Solar System: A Dynamic Cosmic Neighborhood

Our solar neighborhood continues to be explored and understood through science.