Celestial Simulation vs Zenith

Celestial Simulation Experience the universe as it truly moves. Celestial Simulation is a high-fidelity, physics-based app that lets you explore and understand celestial motion through real simulations—not animations or guesses. Every event is driven by time, location, and real celestial mechanics. From eclipses and planetary motion to lunar occultations and chaotic three-body dynamics, the app turns complex astronomy into intuitive, visual experiences. Observer-Based Simulation Your location matters. Set your observing position on Earth and watch how celestial events change with latitude, longitude, and time. Every simulation adapts instantly to your chosen place and moment. Solar System Geometry Explore the mechanics of the inner solar system: - Annular and hybrid solar eclipses with umbra and antumbra geometry - Planetary conjunctions and minimum angular separations - Mercury and Venus elongations for optimal visibility - Retrograde motion visualized over days and weeks - Transits of Mercury and Venus across the solar disk Most simulations are continuous and time-accurate. Lunar Occultations See how the Moon moves through the sky: - Occultations of bright stars and planets - Local and global visibility bands - Geometry that explains why an event is visible from certain locations Three-Body Dynamics Go beyond classical orbits and explore real gravitational complexity: - Circular Restricted Three-Body Problem (CR3BP) - Lagrange points L1–L5 with stability insights - Chaotic motion in non-rotating frames - Extreme sensitivity to initial conditions - These simulations reveal how real spaceflight dynamics and celestial chaos work. Special Focus: Total Solar Eclipse 2026 (Europe) A total solar eclipse will cross Europe in 2026 — a rare and unforgettable event. Celestial Simulation lets you explore the full path of totality, simulate eclipse geometry from different locations, and understand how timing and position affect what you will see. Use the simulation to: - Compare observing locations across Europe - Visualize eclipse paths and shadow motion - Plan where and when to experience totality Whether you are preparing a journey or simply exploring the mechanics behind the event, the app helps you understand why the eclipse unfolds the way it does. Built for Exploration - Interactive time control - Clean, focused visualizations - Designed for learners, enthusiasts, and curious minds - No clutter, no gimmicks—just the universe in motion Celestial Simulation is a pocket laboratory for understanding how the sky actually works. Whether you’re learning, teaching, or simply fascinated by celestial mechanics, this app lets you see the physics behind the beauty.

Zenith shows you the real night sky, wherever you are, and then lets you leave the Earth to explore it. POINT AND SEE Hold your iPhone up to the sky and Zenith follows it. Stars, planets, the Moon, the Milky Way and the constellations appear exactly where they are above you. Turn on the camera to see them over your own view. ACCURATE BY DESIGN Nearly 900,000 stars from real catalogues, more than 13,000 galaxies, nebulae and clusters, and the Sun, Moon and planets computed for your place and time. Positions are checked against NASA JPL. TONIGHT AND EVENTS See what is worth looking at tonight, when, and which way to face. Plan ahead with eclipses, meteor showers, supermoons and planets at their best, for your city or anywhere on Earth, with tips for seeing them. Get alerts for ISS passes and big events, and add the Tonight widget to your Home Screen. SATELLITES Watch the International Space Station, Tiangong, Hubble and more cross the sky, with their paths and the next time they pass over you. Show every active satellite, including Starlink trains. TIME TRAVEL Wind the sky forward or back. Watch the planets wander, find the sky on the night you were born, or travel thousands of years to see the stars drift. ZOOM IN LIKE A TELESCOPE Zoom into Jupiter, Saturn and the other planets right from the sky view and see their real faces, with the right phase and the Great Red Spot where it is tonight. FIND ANYTHING Search for any star, planet, constellation, galaxy, nebula or satellite, or browse by category, and Zenith turns you straight to it. TURN OFF GRAVITY Lift off from where you stand and fly through the solar system. Zoom down to the surfaces of Mars, Jupiter, Saturn and the Moon, give them a spin, and land on the Moon at the Apollo 17 site or on Mars at Jezero crater to stand inside real NASA panoramas. Fly into the Orion Nebula and the Pillars of Creation, visit nearby stars and Earth-like planets, see the Milky Way from outside, travel to Andromeda and other galaxies, and approach real black holes, drawn with the physics of light bending around them. MADE FOR THE DARK Night mode turns everything red to protect your night vision. VoiceOver tells you what you are pointing at. PRIVATE No account, no ads, no tracking. Zenith works offline. It only goes online when you turn on satellites or download optional high detail planet images. Works on iPhone and iPad.