Setting Your Location, and Why It Changes Everything

Time and place are the two inputs that build every sky. Change the moment and the planets move; change the place you're standing and everything above the horizon rearranges entirely, even at the exact same instant — the reason why is the same altitude-and-azimuth math covered at altitude, azimuth, and right ascension. The location controls on the sky map are small — two number fields and one button — but they carry more weight than their size suggests.

Where the controls live, and what they're standing in for

In the control rail, the location fields sit in their own section labeled "Where you are," directly below the time controls covered in time controls: scrub the sky forward and backward. There are exactly three controls here: a Lat field, a Lon field, and a button labeled Use my location. A separate live readout — your current label and coordinates to two decimal places — is pinned to the bottom-left of the sky itself, next to the clock, so you can always check where the map thinks you're standing without opening the rail at all.

Typing coordinates in by hand

The Lat field accepts values from negative 89.9 to positive 89.9; the Lon field accepts negative 180 to positive 180. Both update only when you click or tab away from the field — type a new number and nothing happens to the sky until you leave the box, at which point the whole scene recomputes for the new point and the location label switches to Custom. That's a deliberate design choice: it means you can type a multi-digit coordinate carefully without the sky lurching mid-keystroke.

Note the boundary at exactly 90 degrees latitude, the geographic poles: the field stops just short of it, at 89.9. That's not an arbitrary rounding choice. Our chart engine's own Ascendant and Midheaven calculations are explicitly undefined inside the polar circles, above roughly 66 degrees latitude, where the geometry that produces a rising sign breaks down — see your rising sign explained for what that geometry actually is. Push your custom coordinates up near the pole and you're in territory the astrology half of this page was never built to handle cleanly, even though the astronomy half will keep rendering stars just fine.

Letting the browser do it for you

Use my location asks your browser for permission to share its own geolocation and, if you grant it, sets both fields automatically and switches the label to My location. It's the fastest way to see your actual local sky, but it depends entirely on what your device and browser are willing to report — on a laptop without GPS, that's often a rougher estimate than a phone's would be. If you decline the permission prompt, nothing changes and the map quietly keeps whatever location it had before.

Until you touch either control, the map's default observer point is New York City, at roughly 40.71 degrees north and 74.01 degrees west. That's the starting sky everyone sees before they set anything themselves.

The one honest limit worth knowing

Here is the detail most planetarium tools don't tell you, and ours does, if you read the fine print in the sky chart panel: the natal chart — the "Rising," "Midheaven," placements table, and "Your transits" sections — is computed using whatever observer location the Lat and Lon fields currently hold, not a geocoded birth city typed in separately. There is no birth-location field anywhere on this page, only a birth date and time. If you were born somewhere other than where you currently have the map's location set, your chart's houses and rising sign will reflect the current location, not your actual birth city, unless you manually move the Lat and Lon fields to match where you were born before checking your chart.

This matters because your birth time alone isn't enough to compute an accurate Ascendant — the rising sign changes by roughly one sign every two hours, and it also shifts with longitude at a fixed moment, which is exactly why the observer point drives it directly. For the deeper mechanics of how a rising sign gets calculated from time and place together, see reading your sky chart, and if you haven't opened the control rail before at all, how to use the Real Sky map is the starting point for every section of it, this one included.

What this means for you tonight

If you've saved a birth date but were born somewhere other than wherever the map is currently centered, open the Lat and Lon fields right now and change them to your actual birth coordinates before you trust your rising sign or your placements table's houses — the sign positions of the planets themselves barely move with location, but the houses and the Ascendant absolutely do, and that's the part this page is honest enough to put in writing rather than quietly fudge.