Astronomy
Celestial coordinates, sky motion, telescopes, stellar observation, and practical sky knowledge.
Syllabus
Domains of knowledge & reasoning.
GAAC tests six formal domains across both the individual qualification round and the collaborative team knockout. Mastery of each field is essential for top performance.
Six Domains
Formal areas for qualification and team rounds.
Astrophysics
Stellar physics, radiation, spectra, compact objects, galaxies, and physical interpretation.
Planetology
Planetary systems, surfaces, atmospheres, orbital behavior, and comparative planet science.
Cosmology
Expansion, large-scale structure, cosmic distances, early-universe ideas, and observational evidence.
Observational Astronomy
Data reading, charts, images, measurement, instrument limits, and observational reasoning.
Orbital Mechanics
Kepler's laws, orbital elements, gravitational interactions, two-body dynamics, and trajectory prediction.
Round Structure
How each round uses these domains.
Preview the question format of each round and download a professional sample paper before you compete.
Global Astronomy & Astrophysics Challenge
ROUND 1
A Preview of the Question System
40 MCQs · Full Solutions
Round 1 - Individual
40 Multiple-Choice Questions · 1 Hour
The sample paper includes full solutions and covers observational astronomy, astrophysics, planetology, cosmology, orbital mechanics, and space missions.
Download Sample Paper
Global Astronomy & Astrophysics Challenge
ROUND 2
A Preview of the Question System
10 Free-Response · Solutions
Round 2 - Knockout
10 Problem-Solving Questions
- 3 Observational Astronomy questions
- 4 Astrophysics questions
- 2 Cosmology questions
- 1 Planetology question