Earth and space for high school: study cards over three tiers, the tricky ones, a practice quiz at three levels — Foundation, On-Level, and Challenge — and a lab where you put the universe's story in order from the Big Bang to a breathable Earth, label Earth's layers, graph sixty years of CO₂ from Mauna Loa, and argue from the fingerprints what is warming the planet and why it isn't the Sun. Work here, or print it and use a pencil — both count.
An ellipse. It has a center, like any oval — and it also has two special points called foci.
The Sun sits at a FOCUS of the ellipse, not at the center. That is why a planet has a near end and a far end to its orbit — and it moves fastest at the near end, slowest at the far one.
What people get wrong
⚠️People often think…
The Sun is burning, the way a fire burns.
Burning is a chemical reaction and would have used the Sun up in a few thousand years. The Sun runs on FUSION — hydrogen nuclei pressed into helium — which releases millions of times more energy per kilogram. It is not fission either.
Fusion: hydrogen into helium.
⚠️People often think…
Earth’s core is solid all the way through.
The OUTER core is liquid iron, and its motion is what generates the magnetic field. The INNER core is solid — hotter still, but held solid by immense pressure. Two layers, two states.
Outer liquid, inner solid under pressure.
⚠️People often think…
All the elements were made in the Big Bang.
It produced essentially only hydrogen and helium. Everything heavier — the carbon in you, the iron in your blood, the oxygen you breathe — was fused inside stars and scattered when they died.
Hydrogen and helium first. Stars made the rest.
⚠️People often think…
One brutally cold winter settles an argument about climate.
One season is weather. Climate is a thirty-year average, and a single extreme year sits inside the noise of any long record. The same rule cuts both ways — one hot summer does not settle it either.
Thirty years, not one season.
Fused, condensed, orbiting, layered
1Watch one
Why does a comet move so fast near the Sun and so slowly far out?
Its orbit is a long ellipse with the Sun at one focus.
Near the Sun, gravity is far stronger, so it is pulled hard.
Far out, gravity has weakened and it coasts.
Fastest at the near end, slowest at the far end — which is why comets appear briefly and vanish for decades. ✓
2Do one with me
Fill in what powers what.
The process that powers the Sun is
The Sun sits at a
The layer of the core that is liquid is the
💬One sentence, then you move on
Why can the Sun not be running on ordinary burning?
3Try one
Where was the carbon in your body made?
I want a hint first
Fusing light elements into heavier ones takes enormous heat and pressure. What object has that?
💬Last one — then you're done here
Why does one extreme season not settle a climate question?
Where this goes
Where this lives
Why a compass points where it does, why GPS satellites need their clocks corrected, why a thirty-year normal is the number a farmer or a roofer actually plans against.
What this feeds
Next comes chemistry, where the atoms themselves get counted.
Name one instrument people use to measure something they cannot reach.
One card at a time — tap “Show me” to check yourself, then Next. Start at Foundation; when those feel easy, climb.
Helpful Hints
🪜 Earth and space — the ladder
The universe began 13.8 billion years ago and is still expanding — redshift says so → stars fuse hydrogen into helium and, in their deaths, into everything heavier → our Sun and planets condensed from that debris 4.6 billion years ago → gravity holds the planets in ellipses; Kepler’s laws give the speeds and the years → Earth’s inner heat sorted it into crust, mantle, outer core, inner core, and drives the plates → greenhouse gases keep the surface about 33 °C warmer than bare rock; feedbacks amplify or dampen any change → CO₂ 280 → 420 ppm, +1.2 °C, no carbon-14 in the new carbon, a cooling upper atmosphere: the warming is measured, fast, and ours.
Every claim in this unit rests on something measured — a redshift, a spectrum, a seismic shadow, a gas reading on a mountain. The story is enormous, but it is built from instruments, not opinions.
Big story, small instruments.
⚠️ Tricky ones
The Sun does FUSION (hydrogen → helium), not fission and not burning.
The Big Bang made only hydrogen and helium. Every atom heavier was made in a STAR.
The Sun sits at a FOCUS of the ellipse, not the center — and planets speed up when closest.
The OUTER core is liquid (magnetic field); the INNER core is solid, kept solid by pressure.
One cold winter is WEATHER. A thirty-year average is CLIMATE. Don’t argue trends with single days.
“The climate changed before” is TRUE — and it proves CO₂ and temperature are coupled. The new thing is the RATE.
Volcanoes emit about 1% of what humans do. The Sun has been flat since the 1980s.
📊 The climate evidence — the chart
Measurement
What it reads
What it rules in or out
CO₂ at Mauna Loa
317 ppm (1960) → 412 (2020); 280 before industry
the greenhouse gas is rising, and faster each decade
global temperature
about +1.2 °C since 1880
the warming is real and measured, not modeled
carbon isotopes
the air’s carbon-14 and carbon-13 shares are falling
the new CO₂ is fossil carbon — rules out oceans and volcanoes
upper atmosphere
cooling while the lower atmosphere warms
a thicker blanket, not a brighter Sun — rules out the Sun
satellite infrared
less escaping at CO₂’s wavelengths
the mechanism, seen in action
ice cores
CO₂ and temperature move together for 800,000 years; CO₂ never above 300 until now
coupling is real; today’s level and rate are unprecedented
sea level and Arctic ice
+20 cm; summer ice down about 40%
the effects are already here, and the ice-albedo feedback is running
Seven instruments, each answering a different objection.
🎯 How the test will ask
“What evidence supports the Big Bang?” (redshift of galaxies, the cosmic microwave background, the hydrogen–helium ratio).
“Where did the carbon in your body come from?” (fused in stars, scattered by supernovae).
A cross-section of Earth with letters — “which layer generates the magnetic field, and why?”
CO₂ and temperature data — “describe the relationship and explain the mechanism.”
“Give one positive and one negative feedback in the climate system.”
“A planet is 9 times farther than Earth. How long is its year?” (9³ = 729; √729 = 27).
✅ Can you…
Tell the universe’s story in order, with the two big dates?
Explain fusion, and why the Sun is not “burning”?
Use Kepler’s third law to estimate a year from a distance?
Name Earth’s four layers and the evidence the outer core is liquid?
Explain the greenhouse effect and one feedback of each kind?
Answer “it’s the Sun” and “it’s changed before” with the specific measurement that settles each?
Pick your level
Look back at anything you missed — the hint that appeared is exactly what to reread tonight.
How sure did you feel?
Lab
Work like a scientist: label the diagrams, turn the table into a graph, then write a claim with evidence and reasoning. Every lab checks itself on the spot, and hints are free.
Your practice never leaves this device. There is no account and no sign-in. Your work is saved in this browser only, and you can erase it whenever you want.
Your practice record — saved on this device
This is your record of the module on screen — it stays here and goes nowhere. Independent means you got it right on the first tap; supported means you got it after the explain-and-retry, or marked ‘I had it’ on a revealed answer. Both count, and neither is a grade. If your teacher asks, copy the row or show them this screen.
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The answer key is for a teacher: it prints only from here, for the unit on screen. Print the study packet prints the study pages and a blank quiz — never the answers.