How Catalog, Difficulty Matrix, Lists, Plans, Tonight, the Star Map, Sessions, Ticks, and Observations fit together.
Observing is a cycle: discover objects, organize them into Lists or Plans, then record what you actually see. Nightbase has a dedicated tool for each stage and they pass data between them without you re-typing anything.
The Difficulty Matrix on every catalog page tells you — for your scope, your Bortle-class sky, and your filter — whether an object is Easy, Medium, Hard, Very Hard, or Impossible. Five colour-coded bands, calibrated deliberately pessimistic so "Medium" means truly medium.
Lists vs. Plans: Lists are bookmarks ("objects I like"), Plans are goals with progress tracking ("observe all Messier objects"). Both feed into the Star Map and into Tonight.
Ticks are field-friendly. One tap on the Star Map makes a timestamped, session-attached marker. Tick + Audio records a voice note alongside — pause/resume, restart, append later, AI transcription turns it into searchable text. The screen never leaves night mode.
Your Primary Scope in User Settings quietly powers the personalised row in every difficulty matrix, the default eyepiece view on every object type page, and the visibility ranking on "Nearby in the Sky".
Observing follows a natural cycle: you discover interesting objects, organize them into lists and plans, then go outside and record what you see. Nightbase supports each stage with dedicated tools that pass data between them seamlessly.
The pipeline in one line: Catalog → Lists / Plans → Tonight → Star Map → Session → Ticks → Observations.
The Catalog is the main entry point for discovering objects. It contains over 22,000 astronomical objects across six catalogs: Messier, NGC, IC, Caldwell, Bright Stars, and Solar System. You can search by name or designation, filter by catalog, object type, constellation, magnitude and observability, then sort and paginate the results.
From the Catalog you can select objects and Add to Plan or Add to List using the batch action bar. You can also open objects on the Star Map, or export them as PDF or CSV.
Each object has a detail page with a finder chart, description, ratings, the Difficulty Matrix (see next section), and — for star-like objects — the eyepiece simulator showing how it will appear in a specific telescope + eyepiece combination.
Every catalog object's detail page shows a Difficulty Matrix that answers the question every observer really wants answered: given my telescope and my sky, can I actually see this thing?
Five bands, colour-coded
Each cell in the matrix carries one of five text labels, coloured for glance-reading:
The grading is condition-independent — no moon, no altitude. Those are layered on by the Tonight page. The matrix answers the stable question: is this fundamentally within reach of this scope + this sky + this filter?
Every matrix shows you 3 × 3 cells plus extras:
Set your scope once — Nightbase uses it everywhere
In User Settings you can pick your Primary Equipment. It drives:
It's the single source of truth for "my default scope". Change it on a travel night with a borrowed instrument; change it back when you're home.
The engine compares the object's magnitude and surface brightness against your telescope's limiting magnitude and the sky's background brightness for a given Bortle class. Object type matters — a compact globular cluster and a diffuse galaxy of the same integrated magnitude behave very differently:
Calibrated pessimistic on purpose
The model errs on the dim side. Telling an observer "you can see this" when they can't destroys trust; telling them "this will be hard" when it turns out to be fine is a pleasant surprise. If the matrix says impossible, don't waste a clear night on it.
There are known limitations: some unfiltered emission nebulae (NGC 7000) are rated tougher than they really are, and Epsilon Lyrae's double-double resolution isn't modelled separately — the matrix treats it as a single wide pair.
The same difficulty bands appear as coloured badges on constellation detail pages — a quick way to scan what's worth pulling out of a constellation you're currently under. The "Nearby in the Sky" panel on every object uses your Primary Scope to rank nearby targets from easiest to hardest.
Lists are curated collections of objects that you want to keep track of long-term. Think of them as bookmarks or folders for organizing your interests. A list might be "Best Double Stars", "Galaxies in Virgo", or "Objects I Want to Photograph".
Plans are goal-oriented checklists. Each object in a plan can be marked as observed, giving you progress tracking toward a goal. A plan might be "Complete the Messier catalog", "Spring galaxies for next session", or "Herschel 400 project".
Lists vs. Plans: Use Lists for general collections you want to keep (like bookmarks). Use Plans when you have a specific observing goal and want to track what you've completed.
The Tonight page shows you what's worth observing right now. It combines visibility calculations (what's above the horizon from your location) with object quality ratings to recommend the best targets for the current evening.
The interactive Star Map lets you visually explore the sky. You can pan and zoom across constellations, identify objects, and plan star-hopping routes to your targets. Objects from the Catalog, Plans, and Lists can be displayed as overlays on the map.
A Session represents one night of observing. It captures the shared context for everything you observe that evening: the date, your location, sky conditions, and any general diary notes about the night.
Ticks are quick timestamps you place on objects directly from the Star Map — one tap and done. They're designed for use in the field when you don't want to break dark adaptation by opening forms or navigating away from the map. Think of them as provisional markers: "I looked at this object at this time."
Zero data entry
Tap an object on the Star Map, tap Tick, done. The map stays in night view. The tick records UTC time, object name, type, constellation, and coordinates automatically.
Tap Tick + Audio to create a tick and immediately record a voice note. A night-mode-friendly dialog opens and you can describe what you see while still at the eyepiece. Several features make this usable in the field:
AI transcription, automatically
Every audio note is transcribed to text automatically after upload. Your spoken field impressions become searchable, editable observation text without any typing. When you convert the tick to a full Observation later, the transcription lands in the notes field, with the audio recording attached for reference.
Ticks vs. Observations: Use Ticks in the field to quickly mark what you looked at — add audio to capture impressions in real time. Use Observations when you want to record full details: status (Seen / Not Sure / Not Seen), written notes, equipment, and photos. You can always convert a tick into an observation later when you're indoors.
An Observation is a per-object record within a Session. It captures what you saw (or tried to see) for a single astronomical object on a given night.
Observations link back to the astronomical object in the catalog using natural keys (name and catalog number), so your records stay intact even if the catalog database is rebuilt.
Community Lists let you share your curated collections with other observers and browse lists published by the community. It's a way to exchange observing ideas, benefit from others' experience, and contribute your own expertise.
Very Hard means the object is at the edge of what's achievable — it needs excellent conditions, full dark adaptation, and patient averted-vision technique, and even then you may just catch it. M101 is notoriously low surface brightness, so the model is telling you something real: its faint diffuse light is fighting a bright background. Your options: (a) wait for an exceptional-transparency night at your current site, (b) drive to a Bortle-3 site — the B3 cell for the same scope will usually jump up to Medium or Easy, (c) observe a different, higher-contrast galaxy tonight. Don't spend 20 minutes wrestling with M101 in B5 if the matrix is already warning you.
Because those are observer-specific and time-specific variables that change minute to minute, while the rating is meant to answer a more stable question: "Is this object fundamentally within reach of this scope + sky + filter?" Altitude and moon phase are layered on top by other Nightbase features (Tonight, rise/set times) so the matrix stays comparable across nights. A cell that says Hard under ideal conditions won't magically become Medium because the moon is below the horizon — but it might become Very Hard once the moon rises.
Tap the object on the Star Map, tap Tick + Audio, speak your impression into the night-mode dialog, hit Save. Total time: about 15 seconds. Your dark adaptation is intact, the map stays open, and the tick lands in tonight's session with timestamp, coordinates, audio, and an AI transcription that you can search tomorrow. Later you can convert it to a full Observation if you want to add equipment, status, or photos.
A Tick is a lightweight field marker: timestamp + object + optional audio note. It doesn't count in statistics or Messier-completion totals. An Observation is a full record: status (Seen / Not Sure / Not Seen), written notes, equipment, photos. You promote ticks to observations when you want the record to count — typically the next morning when you can sit with your coffee, listen back to the audio, clean up the transcription, and fill in the scope and eyepiece you used.
Update your Primary Scope in User Settings to the 12-inch. This instantly re-personalises every Difficulty Matrix across the catalog, re-sorts "Nearby in the Sky" panels to use the bigger aperture, pre-selects the 12-inch in every eyepiece simulator, and pre-fills new Observations with it. Change it back to your usual scope when you get home.
On the list's detail page, click Publish. You need a Silver or Gold exam certificate (or to be an admin) to publish. Your profile nickname appears as the author — set it in User Settings first if you haven't. Once published, anyone visiting Community Lists can browse it, copy it to their own collection, or turn it directly into a plan. You can unpublish any time if you want to take it back.
