Night Sky Planner

Before you head to a dark site, see what's worth the trip. Night Sky Planner shows tonight's dark window which objects are visible when. Cell signal optional.

Night Sky Planner works out what's worth looking at tonight from your exact spot, and exactly when to catch it. It's for people who actually go out and look. Everything runs on your phone, so it works at the end of a dirt road with no signal and no account.

It starts with your night: sunset, the three twilights, the moment the sky goes properly dark, then dawn on the way back. It also tracks moonrise, moonset, and how lit the Moon is, since that's usually what washes out a faint target.

Then it scores about 200 objects for where you are tonight: the Messier catalog, NGC and IC deep-sky objects, the brighter stars, and the planets. For each one you get when it clears your horizon, how high it climbs, when it peaks, and the stretch of real darkness when it's worth pointing at.

PLANNING THE NIGHT • Night strip: the whole night on one timeline, dusk through darkness to dawn • Gantt view: every target you've picked and its window across the night, marked at its highest point • Best Nights: ranks the coming nights for one object, so you know whether to go now or wait out the Moon

FINDING IT • POINT ME: hold the phone up and a compass-and-tilt guide walks you onto the target you chose • A printable finder rose with azimuth and altitude, for setting circles or the naked eye

SEEING WHAT IT IS • A sky-survey plate for every object, plus the plain facts: type, magnitude, size, constellation • Thumbnails ship inside the app; tap once to pull the full-resolution plate and keep it for offline nights

MAKING IT YOURS • Filter by gear (naked eye, binoculars, or telescope) and by object type • Set location by GPS, or search a place and drop a pin • A clean share card for the night's list • Paper and night themes, in a plain monospaced almanac style • iPhone and iPad, portrait or landscape

PRIVATE, AND IT STAYS THAT WAY No account, no sign-up, no ads, nothing tracking you. Your location and the motion sensors never leave the phone. It only reaches the network if you ask it to, and only to pull a full-resolution sky-survey plate from CDS in Strasbourg. Offline, it does everything else.

Set your location and see tonight's list. Clear skies.