Earth and space science

Units

1. 1

   The sun and stars

   3 lessons

   1. The Sun: fusion and energy outputExplain that the Sun shines because hydrogen fuses into helium and about 0.7 percent of the mass becomes energy, and use E = mc² and the inverse square law to size what it gives out and what reaches Earth.
   2. Star life cycles and the H-R diagramRead the Hertzsprung-Russell diagram, explain why a cool star can be very luminous, and say how a star's mass sets its lifetime and its end.
   3. Nucleosynthesis in starsSay which elements the Big Bang made, which stars made, and which violent events made, and explain why core fusion stops at iron.
2. 2

   The big bang and the universe

   2 lessons

   1. Redshift and the expanding universeRead a galaxy's redshift from its spectral lines, use Hubble's law to find its speed and distance, and explain that space itself is expanding with no centre.
   2. The cosmic microwave background and element abundancesExplain what the cosmic microwave background is and why it is cold, show that the 25 percent helium of old gas fits the Big Bang and not the stars, and say how three lines of evidence make a theory.
3. 3

   Orbits and the solar system

   4 lessons

   1. Kepler's lawsUse Kepler's three laws to describe a planet's orbit as an ellipse with the Sun at one focus, to compare its speed at perihelion and aphelion, and to find its period from its distance.
   2. Orbits computed from gravityUse Newton's law of gravitation to explain an orbit as continual falling, compute the speed and period of a circular orbit, and explain why orbits change.
   3. Seasons and the tilted EarthExplain that seasons come from Earth's 23.44 degree axial tilt and the Sun's height in the sky, compute the noon Sun altitude for a latitude and date, and show that distance is not the cause.
   4. Moon phases, eclipses and tidesExplain Moon phases as the view of a half-lit Moon, say why eclipses are not monthly and why the Moon always shows one face, and explain two tides a day and spring and neap tides.
4. 4

   Earth's formation and early history

   3 lessons

   1. Relative dating, strata and the geologic time scalePut rock layers and features in order with the rules of relative dating, recognise unconformities, match layers with index fossils, and place the great events on the geologic time scale.
   2. Radiometric datingUse half-lives to turn the ratio of daughter to parent atoms in a mineral into an age, choose a suitable isotope pair, and say why the ages can be trusted.
   3. Earth's formation and early historyGive an evidence-based account of how the Solar System and Earth formed, why meteorites rather than Earth rocks date Earth, where the Moon came from, and what the Hadean Earth was like.
5. 5

   Rocks, minerals and maps

   3 lessons

   1. Latitude, longitude and timeLocate a place by latitude and longitude, find the length of a degree at a latitude, and turn a difference in longitude into a difference in solar time.
   2. Topographic maps and profilesRead elevation, steepness and stream direction from contour lines, use map scale and gradient, draw a profile, and connect contour shapes to the landforms that made them.
   3. Minerals, rocks and the rock cycleDefine a mineral, identify one from several properties rather than colour, tell how igneous, sedimentary and metamorphic rocks form, and describe the rock cycle as a network.
6. 6

   Earth's interior and plate tectonics

   5 lessons

   1. Seafloor spreading and rock agesUse rock ages, magnetic stripes and island chains as evidence for plate motion, and compute a spreading rate from ages at known distances from a ridge.
   2. Plate boundaries and landformsDescribe Earth's plates as slabs of rigid lithosphere, link each kind of boundary to its motion, landforms and hazards, and compute plate speeds and the time for landforms to form.
   3. Seismic waves and Earth's interiorUse P and S waves, their speeds, their bending and the shadow zones to explain how we know Earth's layers and which ones are solid or liquid, and use density to show the interior is denser than the crust.
   4. Mantle convectionExplain that heat from radioactive decay and Earth's formation drives slow convection in the solid mantle, that plates are the cold top of that flow driven mostly by slab pull, and what evidence supports it.
   5. Locating an earthquake epicenterFind the distance to an earthquake from the S-P lag, locate the epicentre by triangulation from three stations, compare magnitudes on the logarithmic scale, and explain how alerts beat the shaking.
7. 7

   Earth's systems and feedbacks

   2 lessons

   1. Earth's spheresDescribe Earth as a system of interacting spheres with two energy sources, trace the water cycle's reservoirs and fluxes, and use residence time to compare how long water stays in each.
   2. Feedbacks: ice-albedo and othersTell positive from negative feedback, work out the ice-albedo feedback with numbers, name other climate feedbacks, and read the Arctic data as evidence.
8. 8

   Water and Earth's materials

   3 lessons

   1. Water's properties and weatheringLink water's molecular properties to frost wedging and dissolving, tell physical from chemical weathering and from erosion, and plan a fair test of what makes rock weather faster.
   2. Erosion and deposition by water, ice and windExplain how speed decides what running water erodes and deposits, how a meander moves, how ice and wind leave different deposits, and how fast erosion is on average and in events.
   3. SoilsDescribe soil as a mixture of minerals, water, air and organic matter that forms from five factors, read a soil profile, link soil to climate, and show that soil loss outpaces formation.
9. 9

   Energy, weather and climate

   4 lessons

   1. Insolation, latitude and the energy budgetExplain why average sunlight is 340 W/m² and not 1361, find sunlight on level ground at a latitude, balance Earth's energy budget with albedo, and show how heat transport moves energy poleward.
   2. The atmosphere and heat transferDescribe the atmosphere's layers and why the troposphere cools with height, name the three ways heat moves, and explain the greenhouse effect with the 390 and 240 W/m² numbers and which gases cause it.
   3. Natural climate drivers: orbit, sun, volcanoesName the orbital cycles and their periods, explain how they pace ice ages with feedbacks, compare the Sun's and volcanoes' effects with human forcing, and use fingerprints to tell causes apart.
   4. Weather maps and station modelsDecode a station model's pressure, wind, cloud cover and temperatures, read highs, lows, isobars and fronts, and use the dew point spread to judge whether rain or fog is likely.
10. 10

    The carbon cycle

    2 lessons

    1. Carbon reservoirs and fluxesBuild a carbon budget from reservoirs and fluxes in gigatonnes, find where human emissions go and how much ends up in the air, and tell residence time from how long added carbon lasts.
    2. Carbon cycle changes over timeUse ice cores, the Keeling curve, isotopes and a past carbon release to compare the present CO₂ rise with natural changes in rate and source, and explain why natural removal is slow.
11. 11

    Life and Earth evolving together

    1 lesson

    1. Life and Earth changing togetherShow with evidence that life changed Earth's air, rocks and soils and that Earth's changes changed life, using the oxygen story, burial, ozone, plants and mass extinctions.
12. 12

    Natural resources and hazards

    2 lessons

    1. Resources, hazards and human historyExplain with evidence how the location of resources shaped where people live and where industry began, and use recurrence intervals and the hazard, exposure and vulnerability split to judge risk.
    2. Managing energy and mineral resourcesTell resources from reserves, compute reserve life and the energy from a plant using capacity factor, compare energy sources by life-cycle emissions, and weigh options with criteria, constraints and weights.
13. 13

    Sustainability and human impact

    2 lessons

    1. Sustainability modelsUse stock-and-flow and logistic models to find sustainable yield, the rule of 70 for exponential growth, footprint and biodiversity measures, and the limits of a model.
    2. Reducing human impactTreat reducing an impact as a design problem with criteria, constraints, tests and refinement, using the I = P × A × T idea, the rational method for runoff and an efficiency calculation.
14. 14

    Climate change: data, models and solutions

    3 lessons

    1. Climate data and model forecastsRead the global temperature record as anomalies, tell trend from noise, explain what climate models do and how they are tested, and compare warming under different emissions scenarios.
    2. Human activity in Earth system modelsAdd up the forcings that change Earth's energy balance, find where the extra heat goes, use climate sensitivity to estimate warming, and use fingerprints and ocean and ice data to attribute the change to human activity.
    3. Mitigation and adaptationTell mitigation from adaptation, use the carbon budget to see how long emissions can continue, compare low-carbon options and stabilisation wedges, and weigh solutions by cost, effect and fairness.