sky.
✳ A LITTLE CURIOSITY. A WHOLE UNIVERSE.

Your universe, in motion.

Explore our celestial neighborhood. Grounded in science. Driven by wonder.

THE SOLAR SYSTEM
Heliocentric view
100%
Drag to rotate · Scroll to explore
TIME MACHINE
A MESSAGE FROM THE SUN

Sunlight takes 8m 19s to reach Earth.

Meet the neighbors08 PLANETS. ENDLESS PERSPECTIVES.

Find your next discovery

Search planets, bright stars, and constellations.

Your place in the universe

The night sky changes with where you stand. Choose a city or enter your coordinates.

Coordinates stay in this browser.

A moment in time

Choose a calendar date, jump to an ancient year, or explore the story before our solar system existed.

Solar orbits: 3000 BCE to 3000 CE. Older positions use a lower-accuracy JPL model. Year jumps land on January 1, 00:00 UTC.

All dates are shown in UTC, independent of observing location.
BUILT ON SOMETHING REAL

Wonder, with the math to match.

Sky is a small, self-contained observatory. Every orbit is calculated in your browser, with no live astronomy service required.

01

The planets follow Kepler.

M = E − e sin E

We solve Kepler’s equation with NASA JPL’s published orbital elements and century rates. Positions use the J2000 ecliptic frame. Orbital time spans 3000 BCE to 3000 CE; outside 1800–2050 it switches to JPL’s lower-accuracy long-range coefficients, including the required outer-planet corrections. Earth represents the Earth–Moon barycenter; UTC approximates ephemeris time.

NASA JPL · Orbital model ↗
02

Your sky starts where you are.

sin h = sin φ sin δ + cos φ cos δ cos H

Fixed bright-star coordinates, approximate precession, and local sidereal time give altitude and azimuth for your location. This is a curated 50-star map, not a complete star atlas. Refraction, nutation, and proper motion are omitted; stellar distances are rounded estimates.

US Naval Observatory · Sky coordinates ↗
03

Space needs a little perspective.

By default, orbital distances use a power curve to make every planet visible. Switch to proportional distances for a shared linear distance scale. Planet sizes and surface illustrations are artistic in both modes. Background stars and the asteroid belt in solar view are decorative.

NASA JPL · Planetary measurements ↗
04

A real Earth, in calculated sunlight.

The globe and Earth portraits use a bundled NASA Blue Marble September 2004 composite with topographic shading. This is a static surface map, not live weather or a historical surface reconstruction. Day and night follow the calculated Sun. Explore daylight reveals the entire surface for browsing; pin colors still show the actual light phase. Natural Earth provides a fallback if the image cannot load.

NASA Earth Observatory · Blue Marble imagery ↗
05

Before there were planets.

Cosmic history is an illustrative timeline from the hot early universe to the present. Its rounded ages follow NASA’s overview. Chapter spacing expands short early epochs. It does not extrapolate present planetary orbits, and it makes no claim to simulate the untested first instant.

NASA · History of the universe ↗

An educational explorer with approximate positions, not a navigation or precision telescope tool. Shortcuts: Space to play / pause · / to search · Esc to close.