The real sky, for any place
Stars, planets, the Moon and the Sun at their true positions for your location, with a horizon, compass points and a sky that darkens through twilight.
Sky view · Planetarium
Look up. The real sky.
A planetarium in your browser: the sky as it looks from where you stand, for any moment from 1600 to 2400.
Charting the sky…
Star data: HYG Database v4.1 by David Nash (CC BY-SA 4.0). Positions of the Sun, Moon and planets: Astronomy Engine by Don Cross. Constellation figures and object descriptions are original to this site.
What you can do
Travel through time
Run the sky forward or back from real time up to a month per second, or jump to any date from 1600 to 2400 and watch the Moon’s phase and the planets move.
Find and learn
Search for any planet, bright star, constellation or deep-sky object, fly to it and read its distance, brightness and when it rises and sets.
✦ Questions
About the sky view
What is in it, how accurate it is, and how to use it.
About 43,000 real stars from the HYG catalogue (6,641 bright or nearby ones: every star visible to the naked eye plus the nearest, and about 36,000 fainter ones down to magnitude 8, which you would need binoculars to see, switchable under Layers), the Sun, Moon and all eight planets, fourteen naked-eye deep-sky objects such as the Andromeda Galaxy and the Orion Nebula, and the traditional figures of 28 well-known constellations, including all twelve of the zodiac, with the ecliptic (the Sun’s path) drawn as a dashed line. You stand on a landscape of grass, hills and pines whose colours follow the light, and by day the sky turns blue. The Milky Way is drawn along the true plane of our galaxy, brightest towards its centre in Sagittarius and cut by the dark dust lane. Its 30,000 tiny star-cloud points are simulated to stand in for the billions of stars too faint and crowded to list, so its position and shape are right but it is not a photograph.
Planets, the Moon and the Sun come from Astronomy Engine, which its authors check against NASA JPL Horizons to about one arcminute, and they include the parallax of where you stand. Stars are placed from the catalogue’s J2000 positions and corrected for the precession of Earth’s axis. Stars’ own motion across the sky is not included, which matters by less than a tenth of a degree for the nearest ones within this century. The code is tested against the astronomy library’s own horizon routine.
Constellation figures are a tradition, not a measurement, and different books draw them differently. The 28 shown are the twelve zodiac constellations plus the most recognisable others, drawn the common modern way from verified catalogue stars. The faint zodiac figures (Cancer, Aquarius and Pisces especially) vary the most between sources. The other constellations are still there as stars; they just do not have lines yet.
The dashed line is the ecliptic, the path the Sun follows through the sky over a year. The Moon and planets always stay close to it. The twelve zodiac constellations are the ones the ecliptic passes through: Aries, Taurus, Gemini, Cancer, Leo, Virgo, Libra, Scorpius, Sagittarius, Capricornus, Aquarius and Pisces. Watching the Sun, Moon and planets stay on this line is a good way to see why.
It is meant to: in daylight the Sun’s scattered light hides the stars, as it does in real life, and only the Sun, Moon and brightest planets show. Step the time forward or backward through twilight to watch stars appear. You can also turn the atmosphere layer off to see the stars at any hour.
Drag to look around, scroll or pinch to zoom, and tap or click an object for details. With the keyboard, use the arrow keys to look around, plus and minus to zoom, space to centre the selected object, Escape to clear it and Home to reset the view.