Solar System Overview and Planet Trivia

SOLAR SYSTEM

• Inner Planets: The first four planets closest to the Sun (Mercury, Venus, Earth, and Mars). They are solid rock and have few moons. Their orbits are short around the Sun. They are also called terrestrial planets.
• Outer Planets: The last four planets farthest from the Sun (Jupiter, Saturn, Uranus, and Neptune). They are made of hydrogen and helium, have ring systems, and many moons. Their orbits are long around the Sun. They are also called Jovian planets.
• Planet Trivia + Order:
  • Mercury: Closest to the Sun, fastest orbital velocity.
  • Venus: Second from the Sun, hottest planet, sometimes called "Earth's twin."
  • Earth: Third from the Sun, has liquid water, life, rotation of 1 day, and revolution around the Sun of 1 year. Axis tilt is 23.5 degrees.
  • Mars: Fourth from the Sun, Olympus Mons is the largest volcano in the solar system.
  • Asteroid Belt: Separates the inner and outer planets, composed of small rocky bodies.
  • Jupiter: Fifth from the Sun, largest planet, has the Great Red Spot.
  • Saturn: Sixth from the Sun, largest ring system.
  • Uranus: Seventh from the Sun, magnetic field is nearly upright.
  • Neptune: Eighth from the Sun, has a Great Dark Spot (Hurricane).
  • Pluto (Dwarf Planet): Not considered a planet anymore.

MINOR OBJECTS

• Moons: Natural satellites of planets, vary widely in composition.
• Meteoroids: Small rocky and metallic objects floating in space.
• Meteor: A flash of light seen in the sky (shooting star), caused by meteoroids burning up in the atmosphere.
• Meteorite: A meteoroid that survives its passage through the atmosphere and lands on Earth's surface.
• Meteor Shower: Caused by comets passing through Earth's orbit.
• Comets: Frozen ammonia, methane, water, rock, and dirt; comet tails always point away from the sun due to solar winds.
• Asteroids: Many orbit between Mars and Jupiter, small rocky objects.

SUN

• Layers (outside → in): Corona, Chromosphere, Photosphere, Conductive/Radiative Zones, Core (where nuclear fusion occurs).
• Nuclear Fusion: Hydrogen fuses into helium releasing light, heat, and energy.
• Average Compared to Other Stars: Medium-sized, medium-mass, with a medium temperature. It is a main sequence yellow star.

UNIVERSE

• Distance:
  • Light Year: Distance light travels in one year; used to measure distances in astronomy.
  • Parallax: Apparent displacement of an object due to a change in the observer's position.
• Star Brightness:
  • Luminosity: Brightness of a star compared to the Sun.
  • Apparent Magnitude (m): Brightness of a star as seen from Earth.
  • Absolute Magnitude (M): Brightness of a star as seen from a standard distance (32 light years).
• Surface Temperatures: Hottest stars are blue, coolest are red.
• Hertzsprung-Russell Diagram: Diagram that shows the relationship between the absolute magnitude of stars and their temperatures.

Constellations

• Patterns of stars in the night sky (88 in total).

Galaxies

• Collections of billions of stars.
  • There are three basic types: Elliptical, Spiral, and Irregular.

Life Cycle of Stars

• Stars have a life cycle, and their mass controls their evolution, lifetime and fate. They are formed from the condensation of interstellar gas.
• Stages include: Stellar Nebula (birthplace of new stars), Main Sequence (most stars are in this category), Red Giants, Supergiants, White Dwarfs.
  • Stars that are smaller in mass end as white dwarfs, and those that are much bigger end in supernova if their mass is sufficient enough to collapse in on themselves eventually ending up as black holes after emitting a huge amount of energy.

Universe Trivia

• The universe is vast, old, and still expanding (red shift).
• Big Bang Theory: Current model for the universe's origin.
• Solar Nebula Theory: Current model for the solar system's origin. The solar system formed through the condensing of the solar nebula. There is an order of events from the origin of the universe to the formation of life on Earth.

Explore the fascinating details of our solar system, including the characteristics of the inner and outer planets. Test your knowledge on planetary trivia, their order from the Sun, and interesting facts about each planet. Perfect for enthusiasts eager to understand our celestial neighborhood!