Space and Earth

Question 1

What is the structure of the universe and its components

Answer 1

The universe consists of galaxies, stars, planets, and other celestial objects arranged in clusters and superclusters, bound by gravity.

Question 2

How do stars form, and what is their life cycle?

Answer 2

Formation: Stars form from collapsing gas and dust clouds (nebulae).
Life Cycle: Nebula → Protostar → Main Sequence → Red Giant/Supergiant → White Dwarf/Neutron Star/Black Hole.

Question 3

What does the Hertzsprung-Russell (H-R) Diagram show?

Answer 3

Classifies stars by absolute magnitude (brightness) and temperature, showing relationships between lifecycle stages.

Question 4

How are distances in space represented?

Answer 4

Represented using scientific notation (e.g., 9.46 × 10¹² km = 1 light year).

Question 5

How do you calculate distances in light years?

Answer 5

Light Year Calculation:
1 light year = distance light travels in one year (~9.46 trillion km).

Question 6

What are the key differences between the Big Bang theory and Steady State theory?

Answer 6

Big Bang Theory: Universe began as a singularity ~13.8 billion years ago and is expanding.

Steady State Theory: Universe has always existed and remains constant.

Question 7

What evidence supports the Big Bang theory?

Answer 7

Cosmic Microwave Background (CMB) Radiation

Redshift of Galaxies

Question 8

What is the timeline of the universe’s major changes?

Answer 8

Big Bang → Formation of hydrogen/helium → First stars → Galaxies → Solar systems → Life on Earth.

Question 9

What is First Nations Australians’ understanding of the universe?

Answer 9

Includes celestial navigation, seasonal calendars, and stories explaining the origins of stars and the universe, emphasizing interconnectedness.

Question 10

What is the biosphere, and what does it include?

Answer 10

The part of Earth that supports life, including all living organisms (plants, animals, microorganisms).

Question 11

What is the lithosphere, and what are its key features?

Answer 11

The solid, outer layer of Earth, consisting of the crust and upper mantle. Includes rocks, minerals, and soils.

Question 12

What is the hydrosphere, and what does it encompass?

Answer 12

All the water on Earth, including oceans, rivers, lakes, glaciers, groundwater, and water vapor.

Question 13

What is the atmosphere, and why is it important?

Answer 13

The layer of gases surrounding Earth, composed mainly of nitrogen (78%) and oxygen (21%).

Question 14

How do the biosphere, lithosphere, hydrosphere, and atmosphere interact?

Answer 14

Exchange matter and energy through cycles like the water and carbon cycles.

Question 15

What are the carbon, nitrogen, and phosphorus cycles?

Answer 15

Carbon Cycle: Movement of carbon through air, water, organisms, and soil.
Nitrogen Cycle: Fixation, uptake by plants, and recycling.
Phosphorus Cycle: Weathering of rocks, uptake by plants, and sedimentation.

Question 16

What role does solar radiation play in climate?

Answer 16

Drives weather patterns, heats the land and oceans, and powers the global climate system.

Question 17

What drives deep ocean currents, and why are they important?

Answer 17

Driven by temperature, salinity, and Earth’s rotation. Regulate climate and support marine life.

Question 18

What are indicators of climate change?

Answer 18

Rising temperatures, sea levels, melting ice, changing species distributions, and biodiversity loss.

Question 19

What is the enhanced greenhouse effect, and how does it link to global warming?

Answer 19

Excessive greenhouse gases trap more heat, leading to global warming.

Question 20

Why is biodiversity important, and what happens if it’s lost?

Answer 20

Maintains ecosystems and species survival. Loss leads to fewer resources and ecosystem collapse.

Question 21

What are strategies to reduce carbon emissions?

Answer 21

Renewable energy, carbon capture, reforestation, and international agreements like the Paris Agreement.

Question 22

What is the Paris Agreement?

Answer 22

A global treaty aimed at reducing greenhouse gas emissions to limit global warming to below 2°C.

Question 23

What is climate modelling, and how is it used?

Answer 23

Climate modelling uses computer simulations to predict changes in climate based on physical laws, current data, and future scenarios (e.g., CO₂ emissions).