Space and Earth Flashcards
What is the structure of the universe and its components
The universe consists of galaxies, stars, planets, and other celestial objects arranged in clusters and superclusters, bound by gravity.
How do stars form, and what is their life cycle?
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.
What does the Hertzsprung-Russell (H-R) Diagram show?
Classifies stars by absolute magnitude (brightness) and temperature, showing relationships between lifecycle stages.
How are distances in space represented?
Represented using scientific notation (e.g., 9.46 × 10¹² km = 1 light year).
How do you calculate distances in light years?
Light Year Calculation:
1 light year = distance light travels in one year (~9.46 trillion km).
What are the key differences between the Big Bang theory and Steady State theory?
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.
What evidence supports the Big Bang theory?
Cosmic Microwave Background (CMB) Radiation
Redshift of Galaxies
What is the timeline of the universe’s major changes?
Big Bang → Formation of hydrogen/helium → First stars → Galaxies → Solar systems → Life on Earth.
What is First Nations Australians’ understanding of the universe?
Includes celestial navigation, seasonal calendars, and stories explaining the origins of stars and the universe, emphasizing interconnectedness.
What is the biosphere, and what does it include?
The part of Earth that supports life, including all living organisms (plants, animals, microorganisms).
What is the lithosphere, and what are its key features?
The solid, outer layer of Earth, consisting of the crust and upper mantle. Includes rocks, minerals, and soils.
What is the hydrosphere, and what does it encompass?
All the water on Earth, including oceans, rivers, lakes, glaciers, groundwater, and water vapor.
What is the atmosphere, and why is it important?
The layer of gases surrounding Earth, composed mainly of nitrogen (78%) and oxygen (21%).
How do the biosphere, lithosphere, hydrosphere, and atmosphere interact?
Exchange matter and energy through cycles like the water and carbon cycles.
What are the carbon, nitrogen, and phosphorus cycles?
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.
What role does solar radiation play in climate?
Drives weather patterns, heats the land and oceans, and powers the global climate system.
What drives deep ocean currents, and why are they important?
Driven by temperature, salinity, and Earth’s rotation. Regulate climate and support marine life.
What are indicators of climate change?
Rising temperatures, sea levels, melting ice, changing species distributions, and biodiversity loss.
What is the enhanced greenhouse effect, and how does it link to global warming?
Excessive greenhouse gases trap more heat, leading to global warming.
Why is biodiversity important, and what happens if it’s lost?
Maintains ecosystems and species survival. Loss leads to fewer resources and ecosystem collapse.
What are strategies to reduce carbon emissions?
Renewable energy, carbon capture, reforestation, and international agreements like the Paris Agreement.
What is the Paris Agreement?
A global treaty aimed at reducing greenhouse gas emissions to limit global warming to below 2°C.
What is climate modelling, and how is it used?
Climate modelling uses computer simulations to predict changes in climate based on physical laws, current data, and future scenarios (e.g., CO₂ emissions).
