Solar System

Origins of the Solar System

  • Theories about the formation of the solar system

Vortex Theory

  • Proposed by Rene Descartes.

  • Suggests that the solar system was formed into bodies with nearly circular orbits due to whirlpool-like motion of pre-solar materials.

  • Descartes explained that:

    • The orbits of the planets are primary whirlpools.

    • Satellites (moons) are secondary whirlpools.

Collision Theory

  • Proposed by George-Louis Leclerc, Comte de Buffon.

  • Indicates planets formed when the Sun collided with a giant comet.

Nebular Theory

  • Proposed by Immanuel Kant and Pierre Simon Laplace.

  • Explains that the solar system originated from a spinning gas cloud that collapsed.

  • As the gas cloud (nebula) flattened, it spun faster leading to:

    • Formation of the Sun.

    • Remaining particles forming the planets.

Planetesimal Theory

  • Proposed by Chrowder Chamberlin and Forest Ray Moulton.

  • Suggests that a star passed close to the Sun, gravitating some parts of it.

  • These parts are called planetesimals, which later became the planets.

Tidal Theory

  • Proposed by James Hopwood Jeans and Harold Jeffreys.

  • A huge tidal wave was created when the Sun collided with another star, producing planetesimals.

Protoplanet Theory

  • Proposed by Gerald Kuiper and Carl Von Weizsäcker.

  • Expands on the nebular theory, explaining the rotation of masses due to varying rotation.

  • The masses are referred to as protoplanets.:

    • Gas and dust accumulate in the middle forming a star.

    • Remaining gas and dust form the planets.

Solar Nebular Theory

  • Involves hydrogen gas, dust, and other gases from gas clouds or nebulas.

  • Stars have a long life span but eventually reach an endpoint where they expand, use more fuel, and ultimately explode.

The Solar System

  • The center of the solar system is the Sun, a star.

  • Contains eight known planets and five dwarf planets:

    • Planets: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune.

    • Dwarf Planets: Pluto, Eris, Ceres, Makemake, Haumea.