Astronomy focuses on observing and understanding celestial objects, from planets and stars to galaxies and beyond, while astrophysics delves into the underlying physical principles that govern their behavior. Together, these disciplines enable us to comprehend the origins of the cosmos. In this guide, you will learn challenging astro(physics) concepts at or even higher than the level of the USAAAO national open, from past USAAAO/IOAA alumni and the best of the best student-teachers.

We have condensed tricky and hard-to-find concepts that frequently show up on the USAAAO into 17 unique handouts, spanning a total of 200+ pages. We implement a highly efficient learning model, where every handout contains multiple practice problems taken from the past few years of USAAAO & IOAA exam archives to immediately polish one's understanding of challenging concepts taught just before. Each of our 17 handouts is free to access and can be easily explored on our handout page.

To ensure a quality educational experience, our team is comprised of highly qualified high schoolers and college students from three continents, whose extensive astronomy knowledge have been recognized nationally and internationally, from Science Olympiad National medalists to the International Olympiad on Astronomy & Astrophysics (IOAA) winners. Our team of experts here at USAAAO Guide will guide you to your success — at USAAAO & IOAA, and beyond.