For a general feature overview, see help.md.
Sky Map needs three things to show the correct sky: the direction your phone is facing, where you are on the planet, and the current time. If the map looks wrong, one of these is likely off.
Sky Map reads direction data from your phone’s built-in compass sensor (magnetometer). If the sensor gives a wrong reading, the map will point the wrong way — and that is a phone hardware issue, not a Sky Map bug. Sky Map cannot automatically correct what the sensor reports; the v1 app offers a manual offset in Settings for phones with a consistent directional error (v2 doesn’t have this option yet).
“I calibrated it but it’s still wrong.” This is the most common misunderstanding. Calibration and accuracy are two different things:
Even after a successful calibration, external magnetic interference will still shift the reading:
| Source | Effect |
|---|---|
| Metal structures, reinforced concrete | Can deflect the magnetic field by 5–30° |
| Car dashboards | Very common — many contain magnets and motor components |
| Magnetic or RFID blocking phone cases | Extremely common cause of persistent compass errors |
| Nearby electronics | Smaller effect but can add up |
Standing near your car? That’ll send your compass off course. Standing on the bleachers at your kid’s sport game? Same. Move away from metal and magnets.
The Earth’s magnetic field is a weak signal. Your phone’s sensor has no way of knowing it’s sitting next to a source of interference — it just reports what it measures.
Things to try, in order:
If a recent phone update broke your compass: this is unfortunately common. Android updates and manufacturer firmware patches can reset or alter how the sensor is calibrated. Sky Map’s sensor code has barely changed in years — if it worked before a system update, the update is almost certainly what changed, not Sky Map.
Sky Map must know where on Earth you are to draw the correct sky. Without location access, v1 defaults to 0° latitude / 0° longitude — a point in the ocean; v2 defaults to Greenwich, UK (51.48°N, 0°). Either way, the map will look completely wrong anywhere else.
Telltale symptom: Polaris (the Pole Star) appearing near the horizon rather than high in the northern sky almost always means Sky Map doesn’t know your location.
To fix:
See also: Google’s guide to app permissions
Sky Map uses your device’s clock and time zone. An incorrect time zone in particular can shift the entire sky by several hours — making it look completely wrong even with a good compass and correct location.
Open the Diagnostics page and check that the time and time zone shown are correct. If they are wrong, fix them in your device’s system settings.
By default, Sky Map draws the Sun, Moon, and planets larger than their true apparent size, so they’re easy to see against the rest of the sky (v1 enlarges them for visibility; v2’s default “Glyphs” disc-size mode holds a fixed on-screen size at any zoom). This is a display choice, not a position error — but it means a solar eclipse (or any close Sun/Moon approach) can look like it starts or ends noticeably earlier or later than the true first-contact time, since the two enlarged disks visually overlap well before or after they actually would at true size.
If eclipse or conjunction timing looks off, switch the Sun/Moon/planets to their true size and check again:
If it’s still off after switching to true size, double-check location and time zone as described above, then send a screenshot via Diagnostics if the problem persists.
This section explains the physics behind why phone compasses fail, for users who want a deeper understanding.
The figure-8 calibration gesture forces your phone’s magnetometer to sample the magnetic field from many different orientations. The sensor’s firmware uses these samples to estimate and cancel out “Hard Iron” distortions — constant magnetic fields produced by permanent magnets in the phone’s own components — and “Soft Iron” distortions from ferrous metals in the chassis that distort external fields.
The goal is to make the sensor’s response consistent as you rotate the phone through all orientations. Think of it as the phone learning to ignore its own internal magnetic noise.
What it does not do: it cannot remove the effect of magnetic sources outside the phone. Once calibrated, the sensor faithfully reports the field it is in — including any bias from a nearby car dashboard or magnetic case.
This is the crucial distinction most guides skip:
A sensor that reads “High” accuracy near a refrigerator will confidently and consistently point in the wrong direction.
Not all magnetometers are equal. Some phones — particularly cheaper models or certain manufacturer lines — have sensors with a persistent bias of 5–15° regardless of environment or calibration. On the v1 app, the manual compass offset (Settings → Sensor Settings (Experts)) is the best available workaround for these devices; v2 doesn’t offer one yet. No app can compensate for a fundamentally poor sensor.
Sky Map can only display what your phone reports. If the phone’s compass is biased, the map will be biased by the same amount. This is a physical property of mobile hardware, not a software problem.
By default (the Glyphs setting) Sky Map draws the Sun, Moon and planets at fixed sizes that are larger than life, so they’re easy to see at any zoom. Those sizes scale with zoom rather than matching the real sky, so two bodies can appear to overlap earlier, later, or for longer than they really do — and whether they overlap can change as you zoom in and out. This is most noticeable during solar eclipses and when the Moon passes close to a planet.
To see a truer picture, change the planets’ Disc size:
If the location and time are correct and True scale still looks wrong, send us your Diagnostics page (see “Still stuck?” below).
Tap anywhere outside the card, or use the back gesture/button, to dismiss it.
If you’re using the older “classic” 3-button Android navigation (rather than gesture navigation), Sky Map runs full screen, so the on-screen Back/Home/Recents buttons aren’t rendered at all. Swipe up from the very bottom of the screen to bring the navigation bar into view, then tap Back to close the card.
--,--,--.v2 shows short yellow onboarding labels the first couple of times you open a screen, to help new users find key controls. They’re not a permanent part of the UI — each label disappears on its own once you’ve seen it twice, and won’t come back after that.
If you’d rather not see the new v2 interface at all, the legacy v1 app remains available and is still actively supported.
Sky Map asks for very little, and every permission is optional — the app opens and shows the sky whatever you choose. Permissions are only requested at the moment you use the feature that needs them (never all at once at launch), and you can change your mind at any time in Settings → Apps → Sky Map → Permissions.
| Permission | When it’s asked | What it’s for | If you don’t grant it |
|---|---|---|---|
| Location (approximate) | The first time you choose automatic location (the welcome tour or the Location screen) | Works out where you are so the sky is drawn for your spot on Earth | The sky is drawn for a default position (v2: Greenwich, UK; v1: 0°/0°), so it will look wrong anywhere else. Fix it by entering your location by hand — nothing else is lost |
| Camera (v2) | When you first turn on the camera (AR) overlay | Shows the live camera picture behind the sky | The overlay stays off. The normal sky map is unaffected |
| Notifications (v2, Android 13+) | When you switch on your first alert (meteor showers, eclipses, satellite passes, tonight’s sky) | Lets Sky Map post those alerts | The alert switch flips back off and no notifications arrive. Everything else works as normal. Alerts are off until you turn them on |
A few other things Sky Map uses don’t show a permission prompt: it can vibrate during the sensor check, check whether you’re online (for the Diagnostics page and map images), and re-arm satellite pass alerts after a reboot. None of these access your personal data.
If you tapped “Don’t allow”: Android will usually ask again the next time you use the feature. After two refusals it stops asking, and you must turn the permission on yourself in Settings → Apps → Sky Map → Permissions. Sky Map points you to this screen when it happens.
Sky Map never needs your contacts, photos, microphone, files or precise (GPS) location. Approximate location is plenty for a planetarium.
No. The sky, star catalogue, planets, constellations, Hubble Gallery images and object descriptions are all built into the app, so Sky Map works fully offline. An internet connection is only used for a few extras (v2):
Yes! Join the beta testing program on Google Play.
Open the Diagnostics page and send it to us. It contains your sensor readings, location, and time info which helps us understand what’s happening on your device.