The ModernEncyclopedia Est. 2026 · A living curriculum · Regularly updated
AST-30 · Sciences · Fully written

Learn Astronomy with any AI

The sky & deep space

Astronomy is the oldest science — the study of everything beyond Earth, from planets and stars to galaxies and the origin of the universe itself. It is humanity's longest-running attempt to work out where, and what, we are.

It's also a field where the frontier moves fast, so pair the map below with the Frontier prompt (web search on) for the latest. Set your level below.

Build a prompt ↓

§01

Compose your prompt

Choose a prompt and a level, then copy
Prompt settings
Subject
AST-30 · Astronomy
This prompt is scoped to Astronomy. Browse the full library to switch subjects.
Which prompt
Your first contact with a topic, pitched exactly at your level.
Level
How deep to pitch it — from a curious start to full university depth.
Topic — optional, narrows the focus
Study time — used by the syllabus builder
British English
Keeps spelling and exam framing UK-style. Turn off for US spelling.
§02

A map of Astronomy

From the solar system to the cosmos

Outward, from the nearby to the beginning of time.

  • The solar system & planetary science — our own neighbourhood, and worlds beyond it.
  • Stars & stellar evolution — how stars live, die, and forge the elements.
  • Galaxies — the vast structures stars belong to.
  • Cosmology — the origin, expansion and fate of the universe.
  • Astrobiology — the search for life elsewhere.
  • Instruments — the telescopes and observatories that make it all visible.
§03

The canon

The astronomers who moved the Earth

Real figures, real revolutions.

  • Ptolemy — the Earth-centred model that held for over a thousand years.
  • Copernicus (1543) — put the Sun at the centre, and started the scientific revolution.
  • Johannes Kepler — the three laws of planetary motion.
  • Galileo — turned the new telescope on the sky and saw moons, phases and craters.
  • Isaac Newton — gravity, which explained why the planets move as Kepler found.
  • Edwin Hubble (1920s) — showed there are galaxies beyond ours, and that the universe is expanding.
  • Vera Rubin — her rotation-curve measurements are key evidence for dark matter.
§04

The live debates

The great unknowns

Astronomy is rich in genuinely open questions.

  • Dark matter and dark energy. Together they're most of the universe — and we don't know what either is.
  • Are we alone? The Fermi paradox: given the scale of the cosmos, where is everyone?
  • The fate of the universe. Endless expansion, or something stranger.
  • How galaxies and planets form. The broad story is known; the details are argued.
  • The multiverse. A real hypothesis, or beyond the reach of science?
§05

Where to start

A route in

A route in — everything runs from the panel above.

  1. Run Orientation on the solar system or on cosmology.
  2. Turn on web search and run The Frontier — discoveries here arrive constantly.
  3. Use Great Debates on "are we alone" or dark matter.
  4. Go outside and look up — then read a good popular astronomy book.

Let the scale do its work. A little astronomy is the best cure for taking yourself too seriously.