USA Astronomy and Astrophysics Olympiad

The USA Astronomy and Astrophysics Olympiad (USAAAO) is a national competition for high school students in the United States of America. The competition consists of multiple rounds, including a First Round and the National Astronomy Championship (NAC). Top performers from USAAAO are invited to represent the United States at the International Olympiad on Astronomy and Astrophysics (IOAA). The competition tests knowledge and problem-solving skills in astronomy, astrophysics, and related fields.

2026 United States
Official Site
General
First Round Problems First Round Solutions
2025
General
First Round Problems First Round Solutions NAC Problems NAC Solutions
Problem 1 (15 pts)
Tracking a Bootes Planet NAC
Problem 2 (15 pts)
The Eye as a Camera NAC
Problem 3 (15 pts)
Sailing NAC
Problem 4 (20 pts)
Gravitational Waves NAC
Problem 5 (30 pts)
Stupendous Man's Saga NAC
Problem 6 (30 pts)
Spherical Cluster NAC
Problem 7 (55 pts)
Planetary Defense NAC
2024
General
First Round Problems First Round Solutions NAC Problems NAC Solutions
Problem S1 (15 pts)
The Boomerang Nebula NAC
Problem S2 (10 pts)
Gegenschein Dust NAC
Problem S3 (15 pts)
Stellar Dodecahedron NAC
Problem M1 (30 pts)
Solar Eclipse NAC
Problem M2 (25 pts)
Neutrino Decoupling NAC
Problem M3 (30 pts)
Spiff's Adventures NAC
Problem L1 (50 pts)
TESS NAC
Problem L2 (50 pts)
The Analemma NAC
2023
General
First Round Problems First Round Solutions NAC Problems NAC Solutions
Problem S1 (10 pts)
White Dwarfs NAC
Problem S2 (10 pts)
The Large Magellanic Cloud NAC
Problem S3 (15 pts)
Culmination Time NAC
Problem M1 (20 pts)
Hyperfine Splitting NAC
Problem M2 (20 pts)
Quantum Fusion NAC
Problem M3 (25 pts)
Into the Wilds NAC
Problem L1 (45 pts)
The Sundial II NAC
Problem L2 (40 pts)
Interstellar Comet NAC
Problem L3 (55 pts)
Finding Friends NAC
2022
General
First Round Problems First Round Solutions NAC Problems NAC Solutions
Problem S1 (10 pts)
Hydrogen Atom Energies NAC
Problem S2 (10 pts)
Binary Mass Function NAC
Problem S3 (10 pts)
Exoplanet Radius Transit NAC
Problem S4 (10 pts)
Posidonius Earth Measurement NAC
Problem S5 (10 pts)
Electron Orbital Energy NAC
Problem M1 (30 pts)
The Speed of Light NAC
Problem M2 (30 pts)
Meteorite Space Station NAC
Problem L1 (45 pts)
The Curious Orbit of James Webb NAC
Problem L2 (45 pts)
The Sundial I NAC
2021
General
First Round Problems First Round Solutions NAC Problems NAC Solutions
Problem S1 (5 pts)
Jupiter NAC
Problem S2 (5 pts)
Solar Interior NAC
Problem S3 (5 pts)
Seeing galaxies NAC
Problem S4 (5 pts)
Eccentric orbit NAC
Problem S5 (5 pts)
Winter sunset NAC
Problem M1 (20 pts)
Relativistic Clock NAC
Problem M2 (30 pts)
Hohmann Transfer NAC
Problem M3 (30 pts)
Space Station NAC
Problem L1 (40 pts)
Big Bang Nucleosynthesis NAC
Problem L2 (35 pts)
Conjunction NAC
2020
General
First Round Problems First Round Solutions NAC Problems NAC Solutions
Problem S1 (5 pts)
Quadrature NAC
Problem S2 (10 pts)
Betelgeuse NAC
Problem S3 (10 pts)
Lyman-Break NAC
Problem S4 (5 pts)
TRAPPIST-1d NAC
Problem S5 (5 pts)
HD 209458b NAC
Problem M1 (15 pts)
Telescoping a binary NAC
Problem M2 (20 pts)
Galaxy Rotation Curves NAC
Problem M3 (15 pts)
Moon NAC
Problem M4 (20 pts)
Black Holes NAC
Problem M5 (15 pts)
Stellar Properties NAC
Problem L1 (30 pts)
M15 Cluster NAC
Problem L2 (25 pts)
Sunspot Magnetograms NAC
2019
General
First Round Problems First Round Solutions NAC Problems NAC Solutions
Problem 1 (7 pts)
Nucleosynthesis NAC
Problem 2 (7 pts)
Lunar Eclipse NAC
Problem 3 (7 pts)
Seeing stars NAC
Problem 4 (7 pts)
Pressure Gradient NAC
Problem 5 (15 pts)
Terrestrial Precession NAC
Problem 6 (15 pts)
Exoplanet detection NAC
Problem 7 (15 pts)
Minimal Black Holes NAC
Problem 8 (15 pts)
A weird universe NAC
Problem 9 (15 pts)
Finding distances NAC
Problem 10 (25 pts)
Magnetic Moments NAC
Problem 11 (25 pts)
Cygnus X-1 NAC
2018
General
First Round Problems First Round Solutions NAC Problems NAC Solutions
Problem S1 (5 pts)
NAC
Problem S2 (5 pts)
NAC
Problem S3 (5 pts)
NAC
Problem S4 (5 pts)
NAC
Problem S5 (5 pts)
NAC
Problem S6 (5 pts)
NAC
Problem S7 (5 pts)
NAC
Problem S8 (5 pts)
NAC
Problem S9 (5 pts)
NAC
Problem S10 (5 pts)
NAC
Problem S11 (5 pts)
NAC
Problem L1 (15 pts)
WASP-14b NAC
Problem L2 (15 pts)
Sualocin and Rotanev NAC
Problem L3 (15 pts)
Fusing hydrogen NAC
2017
General
First Round Problems NAC Solutions
Problem 1 (5 pts)
NAC
Problem 2 (5 pts)
NAC
Problem 3 (5 pts)
NAC
Problem 4 (10 pts)
NAC
Problem 5 (10 pts)
NAC
Problem 6 (10 pts)
NAC
Problem 7 (15 pts)
NAC
Problem 8 (15 pts)
NAC
Problem 9 (15 pts)
NAC
2016
General
First Round Problems First Round Solutions NAC Problems
Problem 1 (6 pts)
NAC
Problem 2 (6 pts)
NAC
Problem 3 (6 pts)
NAC
Problem 4 (6 pts)
NAC
Problem 5 (6 pts)
NAC
Problem 6 (6 pts)
NAC
Problem 7 (6 pts)
NAC
Problem 8 (6 pts)
NAC
Problem 9 (6 pts)
NAC
Problem 10 (6 pts)
NAC
Problem 11 (6 pts)
NAC
Problem 12 (6 pts)
NAC
Problem L1 (30 pts)
NAC
Problem L2 (37 pts)
NAC
2015
General
First Round Problems First Round Solutions NAC Problems NAC Solutions
Problem 1 (2 pts)
NAC
Problem 2 (2 pts)
NAC
Problem 3 (2 pts)
NAC
Problem 4 (3 pts)
NAC
Problem 5 (3 pts)
NAC
Problem 6 (3 pts)
NAC
Problem 7 (3 pts)
NAC
Problem 8 (3 pts)
NAC
Problem 9 (3 pts)
NAC
Problem 10 (4 pts)
NAC
Problem 11 (4 pts)
NAC
Problem 12 (4 pts)
NAC
Problem 13 (6 pts)
NAC
Problem L1 (25 pts)
NAC
2014
General
General Problems General Solutions
Problem 1 (2 pts)
NAC
Problem 2 (2 pts)
NAC
Problem 3 (2 pts)
NAC
Problem 4 (2 pts)
NAC
Problem 5 (2 pts)
NAC
Problem 6 (2 pts)
NAC
Problem 7 (2 pts)
NAC
Problem 8 (2 pts)
NAC
Problem 9 (2 pts)
NAC
Problem 10 (2 pts)
NAC
Problem 11 (2 pts)
NAC
Problem 12 (2 pts)
NAC
Problem 13 (2 pts)
NAC
Problem 14 (2 pts)
NAC
Problem 15 (2 pts)
NAC
Problem 16 (2 pts)
NAC
Problem L1 (12 pts)
NAC
Problem L2 (12 pts)
NAC
Problem L3 (10 pts)
NAC