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Astronomy · Lessons

Astronomy lessons

9 sections · 82 skills · work through the full outline skill by skill — read the long-form lesson or flip through the slide-style version.
Long-form lessonsSlide-style lessons

Astronomy

Practice 82 skills across this outline.

Recommended next
Evidence for Dark Matter
The Milky Way & Galaxies · Galaxies & Dark Matter
Long-form lesson
Weighting distribution
20 categories
Foundations & Observing the Sky · Sky Motions & Coordinate Ideas
7%
The Earth–Moon–Sun System · The Moon
7%
Tools, Data & Scientific Reasoning · Data, Models & Uncertainty
7%
The Milky Way & Galaxies · Galaxies & Dark Matter
6%
Cosmology & the Universe · Dark Energy & Large-Scale Structure
6%
Cosmology & the Universe · The Expanding Universe
6%

Skills

The comprehensive taxonomy of astronomy — drill into a card to work its skills.

The Milky Way & Galaxies · Galaxies & Dark Matter

4 core skills6% total weight
0/4 completed
4 skills to mastery
1
Evidence for Dark MatterRecommended
Long-form
2
Galaxy ClassificationAvailable
Long-form
3
Active Galaxies & QuasarsAvailable
Long-form
4
Galaxy Collisions & MergersAvailable
Long-form

The Milky Way & Galaxies · The Milky Way

5 core skills5% total weight
0/5 completed
5 skills to mastery
1
Stellar PopulationsAvailable
Long-form
2
Milky Way StructureAvailable
Long-form
3
Star Formation in the GalaxyAvailable
Long-form
4
Galactic Center Black HoleAvailable
Long-form
5
Inferring Galactic StructureAvailable
Long-form

Cosmology & the Universe · Dark Energy & Large-Scale Structure

5 core skills6% total weight
0/5 completed
5 skills to mastery
1
Cosmic InflationAvailable
Long-form
2
Evidence for Dark EnergyAvailable
Long-form
3
Large-Scale StructureAvailable
Long-form
4
Dark Matter vs. Dark EnergyAvailable
Long-form
5
Fates of the UniverseAvailable
Long-form

Cosmology & the Universe · The Expanding Universe

5 core skills6% total weight
0/5 completed
5 skills to mastery
1
Big Bang EvidenceAvailable
Long-form
2
Hubble's LawAvailable
Long-form
3
Cosmic Microwave BackgroundAvailable
Long-form
4
Lookback TimeAvailable
Long-form
5
Age of the UniverseAvailable
Long-form

The Solar System · Giant Planets, Moons & Small Bodies

3 core skills2% total weight
0/3 completed
3 skills to mastery
1
Giant Planets ComparisonAvailable
Long-form
2
Small Solar System BodiesAvailable
Long-form
3
Geologically Active MoonsAvailable
Long-form

The Solar System · Terrestrial Planets & Geology

4 core skills4% total weight
0/4 completed
4 skills to mastery
1
Planetary Surface ProcessesAvailable
Long-form
2
Venus's Runaway GreenhouseAvailable
Long-form
3
Terrestrial Planets ComparisonAvailable
Long-form
4
Mars & Past WaterAvailable
Long-form

The Solar System · Formation & Overview

5 core skills5% total weight
0/5 completed
5 skills to mastery
1
Impact Cratering & AgeAvailable
Long-form
2
Planetesimals & Planetary FormationAvailable
Long-form
3
Nebular TheoryAvailable
Long-form
4
Inner vs. Outer Solar SystemAvailable
Long-form
5
Terrestrial vs. Giant PlanetsAvailable
Long-form

Stars & Stellar Evolution · Stellar Evolution End States

4 core skills3% total weight
0/4 completed
4 skills to mastery
1
SupernovaeAvailable
Long-form
2
Stellar Evolution PathwaysAvailable
Long-form
3
White DwarfsAvailable
Long-form
4
Neutron Stars & Black HolesAvailable
Long-form

Stars & Stellar Evolution · Measuring Stars & the H-R Diagram

5 core skills4% total weight
0/5 completed
5 skills to mastery
1
Luminosity vs. BrightnessAvailable
Long-form
2
H-R DiagramAvailable
Long-form
3
Star Color & TemperatureAvailable
Long-form
4
H-R Diagram & EvolutionAvailable
Long-form
5
Stellar ParallaxAvailable
Long-form

Stars & Stellar Evolution · Stellar Structure & Energy

4 core skills3% total weight
0/4 completed
4 skills to mastery
1
Stellar Mass & LifetimeAvailable
Long-form
2
Hydrostatic EquilibriumAvailable
Long-form
3
Nuclear Fusion in StarsAvailable
Long-form
4
Energy Transport in StarsAvailable
Long-form

Foundations & Observing the Sky · Timekeeping & Historical Astronomy

3 core skills4% total weight
0/3 completed
3 skills to mastery
1
Historical Models of the Solar SystemAvailable
Long-form
2
Historical Astronomy DiscoveriesAvailable
Long-form
3
Telescopes & SpectroscopyAvailable
Long-form

Foundations & Observing the Sky · Sky Motions & Coordinate Ideas

5 core skills7% total weight
0/5 completed
5 skills to mastery
1
Observing ConsiderationsAvailable
Long-form
2
Celestial Sphere & CoordinatesAvailable
Long-form
3
Latitude & Sky ObservationsAvailable
Long-form
4
SeasonsAvailable
Long-form
5
Daily & Annual Sky MotionsAvailable
Long-form

Gravity, Motion & Light · Light, Spectra & Telescopes

5 core skills6% total weight
0/5 completed
5 skills to mastery
1
Doppler Effect for LightAvailable
Long-form
2
Electromagnetic SpectrumAvailable
Long-form
3
Telescope TypesAvailable
Long-form
4
Spectral Types & CompositionAvailable
Long-form
5
Blackbody RadiationAvailable
Long-form

Gravity, Motion & Light · Gravity & Orbital Motion

5 core skills6% total weight
0/5 completed
5 skills to mastery
1
Orbital EccentricityAvailable
Long-form
2
Newton's Law of GravitationAvailable
Long-form
3
Why Objects OrbitAvailable
Long-form
4
Tidal ForcesAvailable
Long-form
5
Kepler's LawsAvailable
Long-form

The Earth–Moon–Sun System · The Moon

5 core skills7% total weight
0/5 completed
5 skills to mastery
1
Moon PhasesAvailable
Long-form
2
EclipsesAvailable
Long-form
3
Lunar Synchronous RotationAvailable
Long-form
4
Lunar Surface FeaturesAvailable
Long-form
5
Lunar Origin HypothesesAvailable
Long-form

The Earth–Moon–Sun System · The Earth–Sun System

4 core skills4% total weight
0/4 completed
4 skills to mastery
1
TidesAvailable
Long-form
2
PrecessionAvailable
Long-form
3
Earth's Energy BalanceAvailable
Long-form
4
Earth's Axial Tilt & SeasonsAvailable
Long-form

Tools, Data & Scientific Reasoning · Data, Models & Uncertainty

3 core skills7% total weight
0/3 completed
3 skills to mastery
1
Scientific Models in AstronomyAvailable
Long-form
2
Evaluating Astronomical ClaimsAvailable
Long-form
3
Measurement UncertaintyAvailable
Long-form

Tools, Data & Scientific Reasoning · Distance Scale & Methods

2 core skills4% total weight
0/2 completed
2 skills to mastery
1
Standard Candles & RulersAvailable
Long-form
2
Cosmic Distance LadderAvailable
Long-form

Extraterrestrial Life & Modern Topics · Life, SETI & Modern Frontiers

3 core skills6% total weight
0/3 completed
3 skills to mastery
1
Modern Astronomy FrontiersAvailable
Long-form
2
Drake EquationAvailable
Long-form
3
BiosignaturesAvailable
Long-form

Extraterrestrial Life & Modern Topics · Exoplanets & Habitability

3 core skills5% total weight
0/3 completed
3 skills to mastery
1
Factors Affecting HabitabilityAvailable
Long-form
2
Habitable ZoneAvailable
Long-form
3
Exoplanet Detection MethodsAvailable
Long-form