Overview of the Solar System

Study Notes

The solar system is a gravitationally bound system of the Sun and its orbiting objects.
These objects include planets, dwarf planets, moons, asteroids, comets, and other icy bodies.
The Sun, a star, is the central and dominant object, comprising approximately 99.86% of the solar system's mass.
The remaining mass is distributed among the planets and other objects.

Planets are celestial bodies orbiting a star.
They are massive enough for self-gravity to overcome rigid body forces, resulting in a nearly round shape (hydrostatic equilibrium).
They have also cleared the neighborhood around their orbital path.
There are eight planets in our solar system, categorized as terrestrial or Jovian.

Terrestrial planets, also known as inner, rocky, or telluric planets, are closer to the Sun than the asteroid belt.
They are relatively small and dense, primarily composed of rock and metal.
Examples: Mercury, Venus, Earth, and Mars.

Jovian planets, also called gas giants or giant planets, are farther from the Sun than the asteroid belt.
They are much larger and less dense than terrestrial planets, mainly composed of gas and/or ice.
Examples: Jupiter, Saturn, Uranus, and Neptune.

Mercury: Smallest and closest to the Sun, experiencing extreme temperature variations.
Venus: Hottest planet due to a dense atmosphere trapping heat.
Earth: Unique for supporting life due to liquid water, an oxygen-rich atmosphere, and a protective magnetic field.
Mars: Known for ice caps and evidence of past water; its reddish color due to iron oxide in the soil.
Jupiter: Largest planet, mainly composed of hydrogen and helium, with numerous moons.
Saturn: Famous for its prominent ring system, also primarily hydrogen and helium.
Uranus: Distinctive due to its tilted axis, leading to extreme seasonal changes.
Neptune: Farthest planet from the Sun, characterized by strong winds and storms.

Dwarf planets orbit the Sun but have not cleared their orbital regions of other objects.
Pluto, reclassified as a dwarf planet in 2006, is a well-known example.
Other dwarf planets include Ceres, Eris, Haumea, and Makemake.

Planets orbit the Sun in elliptical paths, with the Sun at one focus of the ellipse.
Kepler's Laws of Planetary Motion describe planetary orbital behavior.
Planets rotate on their axes, defining the length of a day.
Orbital periods of planets vary based on their distance from the Sun.