Solar System Concepts

These flashcards cover key vocabulary and concepts related to the solar system as discussed in the lecture notes.

Geocentric Model

An astronomical model which posits that the Earth is at the center of the universe with all celestial bodies orbiting around it.

Heliocentric Model

A model of the solar system that places the Sun at the center, with planets, including Earth, orbiting around it.

Epicycles

A small circle whose center moves around the circumference of a larger one, used in the Ptolemaic model to explain the retrograde motion of planets.

Retrograde Motion

The apparent backward movement of planets as observed from Earth.

Perihelion

The point in a planet's orbit where it is closest to the Sun.

Aphelion

The point in a planet's orbit where it is furthest from the Sun.

Solar Nebula

A large cloud of gas and dust from which the solar system formed.

Astronomical Unit (AU)

The average distance from the Earth to the Sun, approximately 150 million kilometers.

Photosphere

The visible surface of the Sun which is the coolest part.

Sunspots

Dark spots on the Sun's surface caused by convection slowing down, allowing cooling.

Auroras

Natural light displays in the sky caused by particles from the Sun interacting with the Earth's magnetic field.

Dwarf Planet

A celestial body that orbits the Sun and has enough mass to assume a nearly round shape but has not cleared its orbital neighborhood.

Asteroid Belt

A region in space between Mars and Jupiter where most asteroids are found.

Comet

A body of rock and ice that orbits the Sun, originating primarily from the Oort Cloud or Kuiper Belt.

Meteoroid

A small rock or particle from space that can enter the Earth's atmosphere.

Meteor

The flash of light produced when a meteoroid burns up in the Earth's atmosphere.

Meteorite

A meteoroid that survives its passage through the Earth's atmosphere and lands on the Earth's surface.