Messier: Greenberg Companion
110 deep sky objects, offline
About
Explore all 110 Messier deep sky objects with original astrophotographs and historical observing notes. This app provides detailed information on object type, distance, and location, all accessible offline.
What's New in Messier
1.0
August 22, 2026
FAQ
What is Messier: Greenberg Companion?
Messier: Greenberg Companion is an offline reference app that provides detailed information on all 110 objects in the Messier catalog. It includes original astrophotographs, object details, and historical observing notes.
Does Messier: Greenberg Companion require an internet connection?
No, Messier: Greenberg Companion is built to work anywhere and does not require an internet connection. All data, including photographs and descriptions, is stored on your device.
What kind of objects are included in Messier: Greenberg Companion?
The app features all 110 objects from Charles Messier's catalog, which includes galaxies, nebulae, and star clusters visible from the northern hemisphere.
Can I zoom in on the images in Messier: Greenberg Companion?
Yes, you can pinch to zoom on every image within the app, allowing for closer examination of the astrophotographs.
Does Messier: Greenberg Companion collect any user data?
No, the app explicitly states that it collects nothing about you, including no analytics, tracking, or advertising identifiers. It prioritizes user privacy.
What are the original observing notes mentioned for Messier: Greenberg Companion?
For 104 of the objects, the app includes Messier's original observing notes, translated, providing historical context from the night he logged the object.
Is Messier: Greenberg Companion available on Android devices?
Based on the provided data, Messier: Greenberg Companion is currently supported on iPhone and iPod. Information regarding Android availability is not specified.
How often is Messier: Greenberg Companion updated?
The app was last updated on August 22, 2026, with version 1.0. This indicates it is a new release, and future update frequency is not yet established.