Planet

A planet is a celestial body that orbits a star, is massive enough for its gravity to have cleared the area around its orbit, and has a spherical shape.

Characteristics of Planets:

• Orbiting a Star: Planets orbit a star, such as the sun in our solar system.
• Clearing its Orbit: Planets are massive enough to clear their orbits of other debris, such as asteroids and comets, through gravitational interactions.
• Spherical Shape: Due to their own gravity, planets are generally spherical in shape.

The Eight Planets in Our Solar System:

1. Mercury: The closest planet to the sun, Mercury is a small, rocky planet with a thin atmosphere.
2. Venus: Venus is similar in size and composition to Earth but has a thick, toxic atmosphere.
3. Earth: Our home planet, Earth is the only known planet to support life.
4. Mars: Mars is a cold, desert-like planet with a thin atmosphere and evidence of liquid water in the past.
5. Jupiter: The largest planet in the solar system, Jupiter is a gas giant with a complex system of rings and moons.
6. Saturn: Known for its beautiful rings, Saturn is another gas giant with numerous moons.
7. Uranus: Uranus is an ice giant with a unique sideways rotation axis.
8. Neptune: The farthest planet from the sun, Neptune is an ice giant with a dynamic atmosphere and several moons.

Study Guide:

1. What is a planet?
2. List and describe the characteristics of planets.
3. Name the eight planets in our solar system and provide a brief description of each.
4. What is the sun's role in the orbit of planets?
5. Why is Earth unique among the planets in our solar system?

Understanding the concept of planets and their characteristics is fundamental to grasping the structure and dynamics of our solar system and beyond.