Exploring the Solar System Chapter 2

Exploring the Solar System

• Our Solar System is a system of planets and other objects that orbit the Sun, comprising 8 planets, many moons, asteroids, comets, meteoroids, and tiny particles of rocks and dust.

Formation of the Solar System

• The Sun is the largest object in the Solar System, making up about 99% of the system's mass, and holds everything in place by its gravity.

Planets

• A planet is an astronomical body that orbits a star or stellar remnant.
• There are 8 planets in the Solar System, divided into two categories: terrestrial planets and jovian planets.
• The 4 terrestrial planets are Mercury, Venus, Earth, and Mars, whereas the 4 jovian planets are Jupiter, Saturn, Uranus, and Neptune.

Moon

• The Moon is the Earth's closest neighbor in the sky, taking 7 days to complete its orbit around the Earth.
• The Moon has no life due to the lack of air and water, and its surface features mountains and large bowl-shaped depressions called craters.
• Neil Armstrong was the first person to walk on the Moon on July 20, 1969.

Phases of the Moon

• The Moon appears to change shape every night due to its phases, which are:
  • New Moon
  • Waxing Crescent
  • First Quarter
  • Waxing Gibbous
  • Full Moon
  • Waning Gibbous
  • Last Quarter
  • Waning Crescent

Asteroids

• Asteroids are small, rocky objects that orbit the Sun, found mainly in the main asteroid belt between the orbits of Mars and Jupiter.
• Asteroids are classified into four groups: Apollo, Atens, Atiras, and Amor.

Comets

• Comets are celestial objects consisting of a nucleus made of ice, dust, and rocky material, and are like "dirty snowballs" traveling through space.
• When a comet approaches the Sun, the heat causes the ice to vaporize, creating a glowing coma (a cloud of gas and dust) around the nucleus.
• Comets originate from the outer regions of the Solar System and provide valuable insights into the early formation of our universe.

Terrestrial Planets

• Terrestrial planets are composed primarily of silicate rocks or metals and have a compact, rocky surface.
• Characteristics of terrestrial planets include:
  • Solid surface
  • Core containing heavy elements
  • Higher overall density
  • Fewer moons
  • Closer to the Sun
• The four terrestrial planets are Mercury, Venus, Earth, and Mars.

Jovian Planets

• Jovian planets are larger in size and mass, and do not have solid surfaces.
• Characteristics of jovian planets include:
  • Less dense than terrestrial planets
  • Composed of gases
  • Many moons and strong gravitational pull
  • Rings
• The four jovian planets are Jupiter, Saturn, Uranus, and Neptune.

Dwarf Planets

• Dwarf planets are celestial bodies that orbit the Sun, have enough mass to assume a nearly round shape, but have not cleared the neighborhood around their orbit.
• There are five dwarf planets in our Solar System: Ceres, Pluto, Haumea, Makemake, and Eris.

Kuiper Belt

• The Kuiper Belt is a circumstellar disc in the outer Solar System, extending from the orbit of Neptune to approximately 50 astronomical units from the Sun.
• It is similar to the asteroid belt but is far larger and more massive.

This quiz covers the basics of the solar system, including the planets, moons, asteroids, comets, and other objects that orbit the sun. Learn about the formation of the solar system and the characteristics of the planets.