Big Systems And Science Futures (Nsw Year 9-10 Earth And Space Sciences)

Front 1

Astronomical unit

Back 1

The distance between the Earth and the Sun (1AU)

Front 2

Big Bang theory

Back 2

A theory of the origin of the universe.

It states that the universe came into existence about 13 billion years ago, due to the creation of space-time and the partial conversion of energy into matter.

Front 3

Cosmic background radiation

Back 3

The electromagnetic radiation in space that remains following the Big Bang.

This radiation cooled as the universe expanded, and is now at an average temperature of 3 degrees above absolute zero (3 K or -270 C)

Front 4

Galaxy

Back 4

A vast collections of stars that are held together by gravitational forces.

Front 5

Light year

Back 5

The distance light travels in one Earth year.

Front 6

Nuclear fusion

Back 6

The process in which nuclei of light elements join together, with the release of large amounts of energy.

Front 7

Red shift

Back 7

The shift in frequencies of visible spectral lines towards the red end (low frequency) of the electromagnetic spectrum.

A red shift occurs when the object emitting the radiation is moving away from the detector.

A red shift in characteristic emission and absorption spectra from distant stars and galaxies indicates that they are moving away from us. This is used as evidence of an expanding universe.

Front 8

One astronomical unit in kilometres?

Back 8

1 AU = 150 million kilometres

Front 9

One light year in kilometres?

Back 9

1 ly = 9.461 x 10^12 km

Front 10

Nebula

Back 10

A cloud of gas and stellar dust

Front 11

Nova star

Back 11

A star that shines more brightly than usual since its outer layers have been removed by explosions.

Front 12

Supernova

Back 12

A star that is exploding and shines billions of times more brightly than usual.

Front 13

Pulsar

Back 13

A small, very dense object about 20 km across with a mass similar to that of our Sun.

They emit pulses of radio waves as well as short bursts of X-rays and gamma rays along the direction of their magnetic axes.

Front 14

Quasar

Back 14

A compact region surrounding a supermassive black hole. The quasar emits huge amounts of energy due to mass falling onto the black hole's accretion disk.

Front 15

Black hole

Back 15

A region of spacetime with such strong gravitational effects that nothing, not even light, can escape from it.

Front 16

Our Sun, and stars of similar mass, will eventually evolve into...

Back 16

A white dwarf

Front 17

Large stars, 5 to 10 times heavier than our Sun, eventually evolve into...

Back 17

A neutron star

Front 18

Massive stars, 30x to 50x heavier than our Sun, will eventually evolve into

Back 18

A black hole

Front 19

How long does it take for a star like our Sun to form?

Back 19

Around 40 million years.

Front 20

The closest star to our solar system.

Back 20

Proxima Centauri

Front 21

Eons

Back 21

The largest division of the geological time scale.

Front 22

Fossil

Back 22

Remains, or impressions, of past life forms.

Front 23

Igneous rocks.

Back 23

Rocks that have formed from magma or lava.

Front 24

Lithosphere

Back 24

The outer rigid layer of the Earth, including the crust and upper mantle.

Front 25

Plate tectonics

Back 25

A study of the forces that cause the moment of crustal plates.

Front 26

Pyroclastic

Back 26

A volcanic explosion that releases hot rock fragments and ash.

Front 27

Unconformity

Back 27

A break in geological time between younger and older strata.

Front 28

Radiometric dating

Back 28

Determining the age of rocks or fossils using the known half-lives of radioisotopes.

Front 29

Isotopes

Back 29

Versions of elements that have the same atomic number but different mass numbers.

Front 30

Atomic number

Back 30

The number of protons in the nucleus

Front 31

Mass number

Back 31

The number of protons plus neutrons in the nucleus.

Front 32

Seismology

Back 32

The study of earthquakes.

Front 33

Strata

Back 33

Layers of rock.

Front 34

Cenozoic Era

Back 34

Up to 6.5 million years before present day

Front 35

Mesozoic Era

Back 35

Between 248 Ma and 6.5 Ma before present day. This was the era when dinosaurs dominated, until the extinction at the end of the Cretaceous period.

Front 36

Palaeozoic Era

Back 36

Between 545 Ma and 248 Ma before present day.

This was the era which began with a period of rapid evolution. Animals evolved from marine invertebrates to fish, insects, reptiles and amphibians.

The era ended with the largest mass extinction of marine invertebrates.

Front 37

Precambrian Era

Back 37

Up to 545 million years before present day.

Life forms appear in the fossil record in the Archean eon.

Front 38

Convergent plate boundary.

Back 38

Also called a collision zone.

A zone where continental plates push into each other and form mountain ranges.

Front 39

Destructive plate boundary.

Back 39

Also called a subduction zone.

A zone where an ocean plate slides underneath a continental plate.

Front 40

Divergent plate boundary

Back 40

Also called a spreading zone.

Two plates are moving apart, forming new land in between them.

Front 41

Transform fault zone

Back 41

A zone where plates slide past each other, e.g. the San Andreas fault in California.

Front 42

Continental drift

Back 42

How the locations of the continents have changed over geological time.

Front 43

Focus

Back 43

The site where the earthquake originates. This may be deep underground.

Front 44

Epicentre

Back 44

A point on the Earth's surface immediately above the focus.

Front 45

Primary (P) wave

Back 45

A compression wave that can travel through solids, liquids or gases.

Front 46

Secondary (S) wave

Back 46

A transverse shear wave that travels through solid but not liquids or gases.

Front 47

Land surface (L) wave

Back 47

A seismic wave which originates at the epicentre of the earthquake and travels along the surface of the Earth.

These seismic waves travel the slowest and cause the greatest damage.

Front 48

Seismograph

Back 48

A machine for detecting and recording earthquake waves.

Front 49

Richter scale

Back 49

A scale measuring the energy released from an earthquake. It is not a linear scale. An increase in one unit represents approx. 31 x greater energy released.