Planets and Their Classification

Study Notes

A planet is a celestial body that:
- Is in orbit around the Sun.
- Has sufficient mass to assume a hydrostatic equilibrium shape (i.e., it is nearly round in shape).
- Has cleared the neighborhood around its orbit.

Terrestrial planets: Small, rocky planets with a solid surface. Examples: Earth, Mars, Mercury, Venus.
Jovian planets: Large, gas-giant planets composed mostly of hydrogen and helium. Examples: Jupiter, Saturn, Uranus, Neptune.
Ice giants: Large, gas-giant planets composed mostly of water, ammonia, and methane ices. Examples: Uranus, Neptune.

Size: Ranges from Mercury ( smallest, diameter of approximately 4,879 km) to Jupiter (largest, diameter of approximately 142,984 km).
Composition: Varies from rocky to gaseous, with some planets having a solid core and others being entirely gas.
Atmosphere: Some planets have a thin atmosphere, while others have a thick one that traps heat and supports life.
Moons: Many planets have natural satellites, with Jupiter having the most (79).

Earth: Only known planet to support life, with a diverse range of ecosystems and a stable atmosphere.
Mars: Has the tallest volcano in our solar system, Olympus Mons, and is a potential candidate for supporting life.
Venus: Hottest planet, with surface temperatures reaching up to 462°C (863°F).
Jupiter: Has the Great Red Spot, a massive storm that has been raging for centuries.

Planetary formation theories: Include the Nebular Hypothesis, which suggests that planets formed from a disk of material surrounding the young Sun.
Planetary migration: The process by which planets change their orbits over time, potentially affecting the development of life.

A planet must be in orbit around the Sun, have sufficient mass to be nearly round in shape, and have cleared the neighborhood around its orbit.
Planets range in size from Mercury (diameter of approximately 4,879 km) to Jupiter (diameter of approximately 142,984 km).
Composition varies from rocky to gaseous, with some planets having a solid core and others being entirely gas.
Atmospheres range from thin to thick, with some trapping heat and supporting life.

Terrestrial planets are small, rocky, and have a solid surface (e.g., Earth, Mars, Mercury, Venus).
Jovian planets are large, gas-giant, and composed mostly of hydrogen and helium (e.g., Jupiter, Saturn).
Ice giants are large, gas-giant, and composed mostly of water, ammonia, and methane ices (e.g., Uranus, Neptune).

Earth is the only known planet to support life, with a diverse range of ecosystems and a stable atmosphere.
Mars has the tallest volcano in our solar system, Olympus Mons, and is a potential candidate for supporting life.
Venus is the hottest planet, with surface temperatures reaching up to 462°C (863°F).
Jupiter has the Great Red Spot, a massive storm that has been raging for centuries.

The Nebular Hypothesis suggests that planets formed from a disk of material surrounding the young Sun.
Planetary migration is the process by which planets change their orbits over time, potentially affecting the development of life.