Origin of the solar system

• The Solar System consists of the Sun and everything bound to it by gravity, including planets, dwarf planets, moons, asteroids, comets, and meteoroids
• Newton's law of gravitation states that any particle of matter in the universe attracts any other with a force varying directly as the product of the masses and inversely as the square of the distance between them
• The Solar Nebula Theory proposes the formation of the solar system in stages:
• Collapse:

  • A great cloud of gas and dust called a nebula began to collapse due to gravitational interaction and a shockwave from a nearby supernova
  • The cloud spins more rapidly due to the conservation of angular momentum
• Flattening:

  • The solar nebula flattened out as it rotated, forming a bulge in the central region
  • Pockets of dust and gas collected into denser regions, with most materials forming a ball at the center and the rest flattening into a disk
• Formation of Protosun:

  • Protosun is the early stage of the sun's formation triggered by an increase in temperature leading to nuclear fusion
  • 99.85% of all mass in the solar system is in the sun
• Accretion:

  • Small grains collide and stick together until they attract enough particles
• There are two groups of planets in the solar system: terrestrial planets and jovian planets
• The Sun is composed of Hydrogen (72%) and Helium (28%) and is the source of power in the solar system
• The Sun's structure includes the core, radiative zone, convective zone, photosphere, chromosphere, and corona
• Planetary motions involve orbits, Earth's rotation causing day and night, Earth's revolution leading to a year, and seasons due to the tilt of Earth's axis
• Kepler's Laws of Planetary Motion:

  • 1st Law: The path of planets around the sun is elliptical
  • 2nd Law: An imaginary line from the sun to a planet sweeps equal areas in equal time intervals
  • 3rd Law: A planet's orbital period is proportional to the size of its orbit
• Dwarf planets are celestial bodies that do not meet the criteria of a planet, including Ceres, Makemake, Haumea, Eris, and Pluto
• Asteroids are rocky worlds too small to be planets, found in the asteroid belt between Mars and Jupiter
• Comets are icy bodies in space that release gas or dust, possibly bringing water and organic molecules to Earth
• Meteor, meteoroids, and meteorites are small particles from comets or asteroids orbiting the sun
• Geocentric Model:

  • Supported by Ptolemy and Aristotle, with Earth as the center of the solar system
  • Explained retrograde motion with epicycles and deferents
• Heliocentric Model:

  • Supported by Aristarchus of Samos and Nicolas Copernicus, with the sun at the center of the solar system
  • All planets revolve around the sun