Celestial Simulation vs Astrelia

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.

Raise your phone toward the sky and Astrelia shows you what is actually up there: stars, planets, the Moon and the Sun, placed for your exact location and this exact instant. Tap anything and it tells you everything it knows. POINT AT THE SKY Around 8,900 naked-eye stars, sized and coloured the way the eye sees them. Constellation lines, the ecliptic with the live planets, and a Sun and Moon computed with topocentric parallax and atmospheric refraction, so they sit where you can genuinely see them. Pinch to zoom and more names appear. Tap any star to identify it. Scrub time twelve hours forward or back and watch the whole sky move. Aim at something bright and align, and the compass error that ruins most sky apps is cancelled out. TONIGHT One screen for what is happening: the Moon's phase, sunrise and sunset, which planets are up right now and which are below the horizon, meteor showers near their peak, and what is coming — eclipses, oppositions, solstices, greatest elongations. All of it searched out of the live ephemeris, not read from a hardcoded list. NUMBERS THAT MEAN SOMETHING Every object opens into real astrophysics: distance, spectral class, temperature, luminosity, derived radius, orbital elements. Next to them, plain language — the year the light you are looking at left that star, how many Suns it would take to match it, what you would weigh on that planet, where the star falls on the HR diagram, and a one-line biography of its life. Anything unfamiliar has a glossary entry a tap away. THE GALAXY MAP Leave Earth entirely and free-fly a 3D map built from real data: about 25,000 catalogued stars at their true distances, the Milky Way as its real barred spiral, and deep-sky landmarks at their real positions, distances and sizes. Twenty-seven nebulae are built from public-domain telescope photographs, so their shape and colour are the ones the telescope saw — fly into them and they hold up in three dimensions. Fly to a star and its confirmed exoplanets are there, orbiting it. At the galactic centre, Sagittarius A* is rendered by tracing light through curved spacetime: the galaxy behind it genuinely bends around it. CONSTELLATIONS All 88 IAU constellations, plus asterisms, historical figures and cultural skies, each drawn over its real stars. Open any of them in 3D and the familiar shape falls apart into deep space, because a constellation is a line of sight rather than a thing. Astrelia computes all of it on your device from catalogs that ship inside the app. No account, no subscription, no ads, no tracking, and no network needed to use it. Every dataset, algorithm and image behind it is credited in About → Sources. Astrelia has a sister app, Selenia, which reads the same real sky the astrological way.