COSMOS vs Three

COSMOS is a solar system you hold in your hand. This is not a decoration. Every planet sits exactly where it is right now, computed from real orbital mechanics. Where is Jupiter tonight? How are Saturn's rings tilted? Open the app — the answer is there. - REAL ORBITS Positions of all 8 planets and the Moon are computed from Keplerian orbital elements in real time. Scrub through time to see the sky 10 years from now — or the day you were born. - PHOTO-REAL TEXTURES Saturn's rings, Jupiter's Great Red Spot, sunspots and solar granulation — every texture is generated on your device and stays crisp as you zoom. - CONTROL TIME From one second = hours, to one second = years. Watch the Moon change phase and the planets trace their orbits with your own eyes. - EXPLORE FREELY Pinch and swipe from outside the solar system down to a planet's face. Tap any body for details. - FREE FOR EVERYONE - Every feature is free — nothing locked behind a paywall - Just a small banner ad, never covering the view - Works offline, on a plane or on a mountain - Enjoying COSMOS? Leave an optional tip to support development For curious kids asking "why?" For stargazers who want a quiet moment of awe. The real universe, in your pocket. LANGUAGES English, Japanese, Simplified Chinese, Korean, Spanish, French, German

Three bodies. Countless paths. Watch the beauty of gravity unfold. Three-Body Simulation brings abstract celestial motion into a world of orbits you can watch, interact with, and explore. See three bodies pull on one another as their trails gradually draw patterns, and discover how a simple law of gravity produces rich and fascinating motion. Explore 16 classic periodic solutions From the flowing Figure Eight to Butterfly, Moth, and Bumblebee, discover the shapes and rhythms of different periodic solutions. Detailed introductions to each orbit explain the motion behind these patterns. Discover 10,059 three-dimensional periodic orbits Explore published spatial periodic solutions and discover paths that weave and curve through space. Choose an orbit by number or discover one at random, then rotate the view to see its shape from different directions. Try your own gravity experiment Adjust the mass, initial position, and velocity of each body and watch how the orbit changes. You can also explore random three-body motion to see how the bodies approach, circle, and move away from one another. Turn curiosity into understanding Learn about the origins, history, and basic principles of the three-body problem. See the full system of three equations of motion, explore classic periodic solutions, and learn how the 10,059 spatial periodic orbits were discovered. Let the paths you see become a starting point for understanding gravity and motion. Available on iPhone and iPad in ten languages, including Chinese, English, and Japanese. Orbit data, simulations, and introductions are included in the app, so the core exploration experience works offline. The complete orbit catalog, random motion, and custom experiments are unlocked with a one-time in-app purchase.