S1U1 - What is the universe?

Astronomy

The study of the moon, stars, and other objects in space

Universe

Space and all the matter and energy in it

Parsec

A unit of distance that is equal to 3.26 light years (about 31 trillion km). Measures distances to astronomical objects outside the solar system.

Light year

The distance that light travels in one year (about 9.5 trillion km). Measures distances between stars in the Milky Way.

Astronomical Unit (AU)

The average distance between the earth and the sun (about 150 million km). Measures distances in our Solar System.

Describe how Australian Indigenous peoples used the stars

• Position of the sun shows the changing of seasons

• Constellations and patterns in the movement of astronomical objects at different times of the year would should them where to hunt and define different seasons

Australian Indigenous peoples were considered the first astronomers

Oldest structure related to movement of astronomical objects that is 11,000 y.o is located in Australia. Dreamtime stories related to constellations indicate seasons.

parts of the electromagnetic spectrum (weakest to strongest)

1. Radio waves (Weakest)

2. Microwaves

3. Infrared

4. Visible light

5. Ultraviolet

6. X-ray

7. Gamma rays (Strongest)

Electromagnetic radiation

The energy transferred through space by electromagnetic waves.

Telescope

An instrument that collects electromagnetic radiation from the sky and concentrates it for better observation

Star

A ball of extremely hot gas, mostly hydrogen and helium, that undergoes nuclear fusion.

Main sequence star

A typical star that is undergoing nuclear fusion of hydrogen into helium. Our sun is a main sequence star.

Red giant star

A large, old luminous star; has a relatively low surface temperature and a diameter large relative to the sun. Undergoing nuclear fusion of helium into other elements.

White dwarf star

A small, hot, dim star that is the leftover center of an old star

Supergiant star

A star with a diameter up to 1000 times the diameter of the sun; largest of all stars.

Supernova

A gigantic explosion in which a massive star collapses and throws its outer layers into space

Black hole

A region of space having a gravitational field so intense that spacetime is curved to the point that light cannot escape. Formed when a massive stars collapses at the end of its lifecycle.

Neutron star

The small, dense remains of a high-mass star after a supernova

Stellar nucleosynthesis

The production of new elements by nuclear reactions in the core of a star

Galaxy

A collection of stars, dust, and gas bound together by gravity

Exoplanet

A planet that orbits a star outside the solar system

Scientific Theory

A well-tested explanation for a wide range of observations or experimental results.

Big Bang Theory

A theory that explains the sudden development of the universe through the continued expansion from a hot, dense state.

Steady State theory

a theory which states that there was no beginning to the universe and that the universe does not change in appearance.

Red shift

The change in the wavelength of light due to an object moving away from the observer.

Cosmic microwave background

Radiation left over from the Big Bang

Cosmological inflation

The very very very rapid expansion at the very early stages after the Big Bang.

Big Bang nucleosynthesis

Formations of new elements in the first few minutes after the Big Bang before any stars existed.

Habitable zone

A region around a star where liquid water could be present on a planet's surface and potentially have life

Apparent magnitude

The brightness of an astronomical object as seen from Earth.

absolute magnitude

The brightness an astronomical object would have at a distance of 10 parsecs from Earth.