Earth & Space
Planet, climate, stars and the cosmos. 98 topics, from beginner to advanced.
Browse all 98 Earth & Space topics →Featured
Visual showcases to start withSeafloor Spreading
New oceanic crust forms at mid-ocean ridges and moves away, recording Earth’s magnetic reversals.
Convergent Plate Boundaries
Plates collide: one sinks beneath the other, raising mountains and fuelling volcanoes.
The Greenhouse Effect
Gases such as CO₂ absorb outgoing infrared radiation and warm the surface.
Global Wind Circulation
Hadley, Ferrel and polar cells move heat from the equator, bent by the Coriolis effect.
Ocean Currents and the Conveyor Belt
Wind and density differences drive a global circulation of heat through the oceans.
El Niño and La Niña
Shifts in Pacific trade winds and sea surface temperature alter weather worldwide.
Phases of the Moon
We see different fractions of the Moon’s sunlit half as it orbits Earth every 29.5 days.
The Hertzsprung–Russell Diagram
Plotting luminosity against temperature reveals the main sequence, giants and white dwarfs.
Exoplanet Transit Light Curve
A planet passing in front of its star dims the light slightly; the dip reveals its size.
Galaxy Rotation Curves and Dark Matter
Stars at a galaxy’s edge orbit too fast for visible mass alone — evidence for dark matter.
The Expanding Universe
Space itself expands: distant galaxies recede faster in proportion to distance.
Ocean Tides
The Moon and Sun produce two daily tidal bulges; spring tides occur when they line up.
Popular
Classic topics most learners start withThe Water Cycle
Water evaporates, condenses into clouds and returns as precipitation.
Layers of the Atmosphere
Temperature rises and falls through the troposphere, stratosphere, mesosphere and thermosphere.
Earthquakes and Seismic Waves
P and S waves travel at different speeds; the delay between them locates the epicentre.
How Volcanoes Erupt
Magma rich in dissolved gas rises, bubbles expand and pressure drives an eruption.
The Rock Cycle
Rocks continually change between igneous, sedimentary and metamorphic forms.
Why We Have Seasons
Earth’s tilted axis changes how directly sunlight strikes each hemisphere through the year.
Solar and Lunar Eclipses
Eclipses occur when the Sun, Earth and Moon line up and cast shadows.
The Life Cycle of Stars
A star’s mass determines its fate: a quiet white dwarf or a supernova.
How Black Holes Form
When a massive star’s core collapses, gravity overwhelms every force that resists it.
Timeline of the Universe
From the Big Bang to the present: expansion, cooling and the formation of structure.
Formation of the Solar System
A collapsing cloud of gas and dust flattened into a disk that formed the Sun and planets.
Hurricane Formation
Warm ocean water fuels rising air that begins to spin, growing into a tropical cyclone.
All 98 Earth & Space topics
🌱 Beginner
- Seafloor Spreading
- The Rock Cycle
- Earthquakes and Seismic Waves
- How Volcanoes Erupt
- Tsunami Speed
- The Layers of the Earth
- Mohs Hardness Scale
- Geological Time
- How Glaciers Shape Land
- Layers of the Atmosphere
- The Water Cycle
- The Greenhouse Effect
- Phases of the Moon
- Why We Have Seasons
- Distances of the Planets from the Sun
- Greenhouse Effect with No Atmosphere
- Venus-Like Runaway Greenhouse
- Strong Coriolis Deflection
- No Rotation, No Deflection
- A Hot Blue Giant Star
- A Sun-Like Star
- Slow Cosmic Expansion
- Fast Cosmic Expansion
- Seasons with No Tilt
- Seasons with Extreme Tilt
- Full Moon Geometry
- New Moon Geometry
- Earthquake Magnitude and Energy
- Richter Amplitude
- P-Wave and S-Wave Travel Times
- Atmospheric Pressure with Altitude
- Temperature Lapse Rate
- Sea Level Rise from Thermal Expansion
🔧 Intermediate
- Convergent Plate Boundaries
- Divergent Plate Boundaries
- Transform Plate Boundaries
- Radiometric Dating of Rocks
- Weathering and Erosion
- Enhanced Greenhouse Warming
- The Coriolis Effect
- Global Wind Circulation
- Ocean Currents and the Conveyor Belt
- El Niño and La Niña
- Hurricane Formation
- Thunderstorms and Lightning
- Soil Formation
- Solar and Lunar Eclipses
- Ocean Tides
- Surface Gravity of the Planets
- The Habitable Zone
- The Hertzsprung–Russell Diagram
- Timeline of the Universe
- Geothermal Gradient
- Wind Speed and Pressure Gradient
- CO₂ and Radiative Forcing
- Keeling Curve Trend
- Ocean Acidification and pH
- Orbital Speed of a Planet
- Escape Velocity vs Planet Mass
- Tidal Force vs Distance
- Orbital Decay of a Satellite
- Doppler Shift of a Moving Star
- Cepheid Period–Luminosity Relation
- Apparent Magnitude and Distance
- Age of the Universe from Hubble’s Constant
- Orbital Resonance
- How Hurricanes Are Rated
- How Tornadoes Form
- Monsoon Circulation
- Formation of the Solar System
- Formation of the Moon
- Detecting Exoplanets
- Moons of the Planets
🚀 Advanced
- Kepler’s Third Law
- The Life Cycle of Stars
- Stellar Lifetimes
- Inverse-Square Law of Light
- Parallax and Stellar Distance
- Schwarzschild Radius of a Black Hole
- Exoplanet Transit Light Curve
- Galaxy Rotation Curves and Dark Matter
- The Expanding Universe
- Cosmological Redshift
- How Gravity Assists Work
- Cosmic Microwave Background Spectrum
- Roche Limit
- How Supernovae Create Elements
- How Black Holes Form
- Rocket Launch Sequence
- How Telescopes Work
- Carbon Capture and Storage
- Renewable Energy Mix
- The Ocean Carbon Pump
- Coral Reef Bleaching
- Deforestation Feedbacks
- Urban Heat Islands
- Greenhouse Gas Warming Potentials
- Sunlight at the Planets
Frequently asked questions
What will I learn in Earth & Space?
Planet, climate, stars and the cosmos. Each topic has a live animation, a lesson and a quick quiz.
Where should I start?
Try “The Water Cycle” from the Popular list, or any beginner topic in Browse.
Are the topics in a set order?
Browse groups topics by level, with beginner topics first. Each topic’s FAQ names the topic to read before it.
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