MessierMate vs Night Sky Planner

110 deep-sky objects. See which ones are above your horizon right now, sorted by urgency so you never miss one before it sets. MessierMate is the complete companion for deep-sky observing, and it's completely free. No ads. No in-app purchases. Ever. Whether you're under the stars for the first time or chasing the Messier Marathon, the app tells you exactly what's visible from your location right now, helps you plan future nights, and keeps a log of every session. TONIGHT Open the app and instantly see which of the 110 Messier objects are above your horizon, sorted by urgency so you never miss a galaxy that's about to set. Each card shows altitude, compass direction, time until it sets, and an altitude arc so you know exactly when to look. Filter by object type (galaxies, nebulae, star clusters) and minimum altitude, and switch between three card layouts to match your observing style. PLAN Tap any night on the monthly calendar and see dusk time, moon phase, moonrise, and a count of how many objects are visible. Browse your targets in a list or on a timeline that shows when each object rises, peaks, and sets. Star objects to build a target list for the night. The app automatically detects Messier Marathon nights and flags them on the calendar. LOG Record every session with the date, location, duration, and which objects you observed. Add notes and photos to individual objects. Share a session with a friend via a short share code. No account needed on their end to view it. YOUR SKY, YOUR PRIVACY Your GPS coordinates never leave your device. Only your site name and Bortle class are synced to the cloud, never your exact coordinates. There are no ads and no analytics trackers. Guest mode is fully functional: the app works completely offline without an account. BUILT FOR DARK SITES A dark theme and a Red Night mode protect your night vision. The interface is designed to be usable by feel, with minimal taps needed to log an observation while you're at the eyepiece. WHAT'S INSIDE - All 110 Messier objects with real-time altitude and azimuth calculations - Tonight view ranked by urgency, objects setting soonest appear first - Monthly planning calendar with moon phase and object counts - Rising, peaking, and setting timeline for any night - Automatic Messier Marathon opportunity detection - Session log with notes, photos, and shareable codes - Equipment manager for telescopes, eyepieces, filters, and cameras - Bortle scale support for accurate sky darkness settings - Red Night mode for dark site use - Works offline, no internet connection required for sky calculations - Free, with no ads and no in-app purchases Whether you're hunting your first galaxy or completing the catalog for the tenth time, MessierMate keeps you focused on what matters: the sky.

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, and no server of ours for anything to land on. The motion sensors stay on the phone, and when the sky view uses the camera to help you line up on a star, those frames are read and thrown away on the spot — nothing is photographed or saved. It does reach the network for four things: an hourly cloud forecast for your spot, which is the one it fetches on its own; a place search, if you type one; Apple Maps, if you open the map picker; and a full-resolution sky-survey plate from CDS in Strasbourg, if you ask for one. Every bit of the astronomy is computed on your phone, so it all still works with no signal. Set your location and see tonight's list. Clear skies.