IOAA 2026 preparation
Navigate the sky, one problem at a time.
A working problem bank for astronomy and astrophysics olympiads. Every problem carries a hint, a full worked solution, and the reading that gets you there.
- 7
- Topics
- 14
- Problems with solutions
- 10
- Reading resources
- 6
- Olympiad archives
Problem sets by topic
The seven areas the IOAA syllabus keeps returning to.
Spherical Astronomy & Coordinates
2Celestial sphere, coordinate systems, time and rising/setting.
Celestial Mechanics & Orbits
2Kepler's laws, two-body problem, orbital transfers.
Stellar Astrophysics
2Magnitudes, blackbody radiation, stellar structure and evolution.
Planetary Science
2Planets, moons, tides, atmospheres and exoplanets.
Observational Astronomy & Photometry
2Telescopes, resolution, detectors, photometry and spectroscopy.
Galactic & Extragalactic Astronomy
2Milky Way structure, rotation curves, galaxies and dark matter.
Cosmology
2Expansion, redshift, the CMB and the fate of the Universe.
Interactive
The Solar System, turning
Drag to look around, scroll to zoom, tap a planet for its numbers. Sizes and distances are compressed so everything fits on one screen.
Pick a planet to see its distance and orbital period.
National olympiad archives
Past papers with full solutions from IOAA, BAAO, USAAAO, INAO and more — each linked to its official home.
See the archivesReading that actually helps
Textbooks, lecture notes and tools mapped to the topics they cover, so you know what to open next.
Browse reading