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Live Sky Map: Tonight's Sky Over You

The map above is a full-screen planetarium that draws the sky for your exact spot on Earth, right now or at any moment between the years 1700 and 2200. Drag to look around, pinch or scroll to zoom, and tap anything, a star, a planet, the Moon, to learn what it is, when it rises and sets, and whether your own sky is dark enough to show it. The sky you can actually see tonight, explained.

What the map shows

The dome renders about 9,000 real stars, every star brighter than magnitude 6.5, the classic naked-eye limit under a dark sky, drawn from the European Space Agency's Hipparcos catalog with each star's true color. On top of that it computes live positions for the Sun, the Moon and all the planets (plus Pluto), draws the 88 constellation figures with their names, shades the sky through every stage of twilight, and shows the Milky Way as a labeled schematic band. The Moon shows its real phase, with the crescent's horns pointing the correct way for your view, at its average angular size by default.

Below the horizon line the map draws ground, not stars: what you see matches what your horizon actually hides. Everything is computed in your browser by the open-source Astronomy Engine; after loading, the page talks to no third-party service except the optional place lookup (finding or naming a city), and turning on the pointing mode loads one small declination file from this site.

How to read the sky

Direction: the letters around the horizon are compass points; N is due north. Whatever the map shows above the S marker is what you see when you face south. Height: astronomers measure height in degrees of altitude, from 0 at the horizon to 90 straight overhead; your fist at arm's length spans about 10 degrees, so an object at 30 degrees altitude is three fists up. Brightness: star brightness is measured in magnitudes, and the scale runs backward: magnitude 0 is brilliant, magnitude 6 is the naked-eye limit under a dark sky.

To match the map to your real sky, open the layers panel and set your Bortle class, the standard 1 to 9 rating of light pollution. The map then fades exactly the stars your sky hides: a Bortle 8 city sky keeps only a few hundred stars, which is honest, not broken. The same fade runs through twilight, so stars appear in the evening in the true order of brightness, Sirius and the planets first.

What is up tonight?

The strip along the bottom of the map ranks tonight's best objects for your location: the Moon, the visible planets, and more than two dozen famous deep-sky showpieces, each with the time it climbs highest and a dot showing whether it is within reach of your sky and equipment. Tap a chip and the camera flies there. For the full ranked table with rise and set times, see Today in the Sky.

Everything the map can do

• Tap to identify: every star, planet and constellation gets a plain-language card: what it is, how high it sits right now, when it rises, peaks and sets tonight, and whether your eyes, binoculars or a telescope will show it.
• Search with no server to break: type any star, planet, constellation or Messier name (typos are fine) and the camera flies to it. The search index ships with the page: it needs no server.
• Time travel: scrub minutes or centuries, jump to sunset, the middle of the night, or sunrise (computed for the map's location), or play time at up to a day per second and watch the sky wheel.
• Honest realism: the Bortle setting and twilight fade show the sky you will actually see, never a fantasy deep field. The "perfect dark sky" view is labeled as exactly that.
• Red night mode: one tap turns the whole page deep red to protect your dark adaptation at the eyepiece, with a screen dimmer on top.
• Find the planets instantly: colored rings mark every planet that is up, edge arrows point toward the ones outside your view so you can pan straight to them, and opening search with an empty box lists the whole solar system with live positions and rise times.
• Point at the sky (beta, on phones): tap the point-at-the-sky button and the map turns as you move your phone, using the motion and compass sensors. Compasses are only good to about 10 degrees, so if the map sits a little off, tap the object you are really aiming at and press Align (or drag sideways); the correction is remembered on your device, and magnetic declination is corrected automatically.
• Shareable views: the link in your address bar always encodes the exact view: place, time, direction, zoom and selection. Copy it and anyone opens the same sky.
• No ads, no account, no install: the viewer is about 300 KB compressed. It loads in seconds on a phone and asks nothing of you.

Keyboard shortcuts

Arrow keys look around; + and - zoom; , and . step time by ten minutes; / opens search; t opens the time controls; l opens layers; Escape closes any panel. Every control is reachable by Tab, and selections are announced to screen readers.

Accuracy, honestly stated

Sun, Moon and planet positions come from the MIT-licensed Astronomy Engine, accurate to well under a degree and reliable for roughly the years 1700 to 2200; the time scrubber is clamped to that range. Star positions are Hipparcos catalog values in the J2000 reference frame, carried through precession and nutation; annual aberration, up to about 20 arcseconds, is not modeled for stars, which is well over a hundred times below the whole-degree precision this map claims. Stellar proper motion is not applied either; the few fastest-moving bright stars drift by up to about half a degree at the far ends of that range. Atmospheric refraction is applied near the horizon using a standard-atmosphere model; real refraction at the horizon varies by several arcminutes with temperature and pressure. Altitudes and azimuths are shown to whole degrees and times to the minute: no decimal is displayed that the model cannot defend.

What this map deliberately does not do: it does not render photographic deep-sky imagery or a billion-star catalog (the honest naked-eye sky ends near magnitude 6.5), it does not overlay the camera picture (the point-at-the-sky mode moves the map with your phone, but honestly, as a chart: phone compasses are typically within about 10 degrees, so a drag-to-align nudge is built in), it does not predict satellite passes, and it does not control telescopes. Tools that do those things well exist; this page would rather do the visible sky excellently.

Data sources

Stars: the ESA Hipparcos catalog (8,870 stars to magnitude 6.5, with B-V colors). Star names: the IAU Catalog of Star Names. Constellation figures and the schematic Milky Way outline: the d3-celestial project by Olaf Frohn (BSD-3-Clause). Magnetic declination for the point-at-the-sky mode: the World Magnetic Model, on a coarse grid regenerated yearly. All positions computed in-browser by the Astronomy Engine (MIT). Full details on the methodology page.

Sky map questions, answered

What is that bright star I can see tonight?

It is often not a star at all. The brightest steady point in the evening or morning sky is usually Venus or Jupiter, and the brightest true star is Sirius. To find out exactly what you are seeing, set your location on the map above, point the view the same way, and tap the object: the map names it and tells you when it rises and sets.

Is this sky map free? Do I need an account or an app?

Yes, it is free, with no account, no app to install, and no ads on this page. The whole viewer downloads about 300 KB compressed and runs entirely in your browser, so it starts fast even on a slow connection.

How accurate is this sky map?

Sun, Moon and planet positions come from the open-source Astronomy Engine and are accurate to well under a degree, reliable for roughly the years 1700 to 2200. Stars come from the Hipparcos catalog with precession and nutation applied. Altitudes and azimuths are shown to whole degrees and times to the minute, which is what the model honestly supports.

Why does the map show more stars than I can see?

By default the map draws the classic naked-eye sky: about 9,000 stars, down to magnitude 6.5. Most real skies are brighter than that: from a city you may see only a few hundred stars, and from a bright inner city just a few dozen. Open the layers panel and set your Bortle class, and the map will fade out the stars your sky hides. The map also fades stars through twilight, so at noon it honestly shows none.

Does the sky map track or store my location?

No. By default it only guesses a starting city from your device's time zone, entirely on your device. If you tap 'Use my location', your browser's coordinates are used locally to compute the sky, and they are sent once to a geocoding service only to look up your city's name for the label. Nothing is stored on any server and there is no account.

Can the sky map follow my phone as I point it at the sky?

On most phones, yes. Tap the point-at-the-sky button and the map turns as you move your phone, using the motion and compass sensors; iPhones ask for motion permission first. Phone compasses are only accurate to about 10 degrees, so if the map sits a little off, tap the object you are really aiming at (the Sun or Moon works well) and press Align; a gentle sideways drag also fine-tunes it, and magnetic declination for your location is corrected automatically. There is no camera overlay: the map stays a clean, readable star chart.

What time zone are the times on the sky map shown in?

Times follow your device's clock. If you point the map at a place whose local time is more than two hours from yours, a note appears saying how big the offset is, so a sunset listed at 3:40 am will not surprise you. Shared links can carry an explicit time zone, and the sunrise and sunset presets always use the sky location's real solar events.

Keep exploring

Pair the map with Today in the Sky for tonight's full ranked list, the 88 Constellations catalog for every figure's story, the Telescope Calculator to know what your gear can reach, and the Moon Phase Calendar for the month ahead.

No ads run on this page, ever.