MessierMate: Night Sky Tracker
Astronomy Log & Deep Sky Guide
Free · Designed for iPad. Not verified for macOS.
All 110 Messier objects. Tonight. From your exact location. Messier Marathon ready. Free forever. No ads, no subscriptions, no tracking.
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.
New in this update:
- Add observing sites by search, map tap, pasted Google Maps link, or coordinates
- Bug fixes and UX polish
The developer, CosmicFlow Labs LLC, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Linked to You
The following data may be collected and linked to your identity:
- Contact Info
Data Not Linked to You
The following data may be collected but it is not linked to your identity:
- Location
- User Content
- Identifiers
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
- Seller
- CosmicFlow Labs LLC
- Size
- 56.5 MB
- Category
- Reference
- Compatibility
Requires iOS 15.1 or later.
- iPhone
Requires iOS 15.1 or later. - iPad
Requires iPadOS 15.1 or later. - iPod touch
Requires iOS 15.1 or later. - Mac
Requires macOS 12.0 or later and a Mac with Apple M1 chip or later. - Apple Vision
Requires visionOS 1.0 or later.
- iPhone
- Languages
- English
- Age Rating
4+
- 4+
- Copyright
- © 2026 MessierMate