Spinning Camera in Space Captures Physics in Action, Demonstrating teh ‘Dzhanibekov Effect’
HOUSTON, TX – A camera spinning freely aboard the International Space Station (ISS) has demonstrated a interesting and counterintuitive physics phenomenon known as the ”Dzhanibekov Effect,” captured on video by astronaut Don Pettit and shared on social media this week. The video, showing a Nikon Z9 camera flipping 180 degrees mid-rotation, illustrates a theorem that predicts such behavior in rigid bodies with uneven mass distribution.
The “tennis racket theorem,” as it’s sometimes called, explains that an object with three distinct moments of inertia will unexpectedly flip its axis of rotation, even without external forces. Pettit’s demonstration,recorded in microgravity,vividly showcases this principle. His Nikon Z9, equipped with a Nikon 14-24mm f/2.8 lens and Speedlite flash, spins for several seconds before flipping and continuing its rotation on a new axis, repeating the process multiple times.
rotating object were it will flip its axis by 180 degrees, is demonstrated in microgravity with our camera. pic.twitter.com/G45oNvb5Lg
– don Pettit (@astro_Pettit) November 20, 2025
Remarkably, Pettit also captured footage from the rotating camera itself, providing a unique perspective on the effect.
A new spin on orbital video. pic.twitter.com/hgdgg25XnL
– Don Pettit (@astro_Pettit) November 24, 2024
Pettit documented the phenomenon during his recent ISS mission, which spanned from September 11, 2024, to April 20, 2025. Beyond the spinning camera, Pettit collaborated with National Geographic photographer Babak Tafreshi on a photo series capturing the same scenes from space and Earth. He also utilized a custom-built star tracker designed by Ted Kinsman of RIT, enabling unique astrophotography opportunities from the ISS.
Image credits: Don Pettit