Origins of The Universe Flashcards
Astronomy
The study of the universe and everything in it.
Geocentric Model
The Sun, Moon, planets and stars all orbit the Earth which does not move.
Heliocentric Model
Planets orbit the Sun instead of the Earth.
Universe
Made up of everything that exists, including planets, stars, galaxies and all forms of matter and energy.
Big Bang Theory
The idea that scientists use to explain how our universe was formed.
Galaxy
A large group of stars, dust, gas and dark matter held together by gravity.
Antimatter
The mirror image of matter. Every particle of matter has a corresponding particle of antimatter.
Celestial Body
Any natural body outside of the Earth’s atmosphere.
Moon
A natural satellite which orbits a planet.
Star
A ball of heat-radiating gas that is hed together by gravity
Nuclear Fusion
Involves two small nuclei joining together to form a larger nucleus.
The Sun
The closest star to Earth.
Light Year
The distance that light travels in one year. Light-years are often used in astronomy to describe the distance to faraway stars and galaxies.
Asteroids
Lumps of rock that orbit the Sun.
The Three Asteroid Types:
- C-type asteroids are made up of carbon compounds.
- S-type asteroids are made up of stony material.
- M-type asteroids are mostly made up of metals, such as iron.
Comet
A small lump of ice and dirt that orbits the Sun.
The Three Parts of A Comet
- The Nucleus: Made of dust and ice.
- The Coma: A fuzzy outline or atmosphere caused by the Sun’s radiation, made up of carbon dioxide, dust and water vapour.
- The Tail: Made up of gas and dust produced by the nucleus.
Terrestrial Planets
The four inner planets are called terrestrial planets because they are made up of rock. They are Mercury, Venus, Earth and Mars.
Gas Giants
The four outer planets are called gas giants because they are mainly made of gases hydrogen and helium. They are Jupiter, Saturn, Uranus and Neptune.
Mercury
Small for a planet, roughly the same size as the Moon.
Has no atmosphere and is covered in craters.
The side of the planet facing the Sun is very hot (approximately 430 degrees celsius).
Venus
Similar in size to Earth.
Covered in clouds of sulfuric acid and has an atmosphere made of carbon dioxide.
It is even hotter on Venus than on Mercury.
Earth
Fifth largest planet.
Only planet with liquid water, oxygen and living things.
It is at the right distance from the Sun and has the right chemicals to support life.
Mars
Iron oxide gives Mars its reddish colour.
Has a dusty, rocky surface, calm conditions and a thin atmosphere of carbon dioxide.
It is rocky, with mountains and valleys.
Jupiter
The largest planet.
Has no solid surface and is mainly made of hydrogen and helium.
It has many moons, some of which have volcanoes.
