Last updated: July 2026 · draft
Overview
Transit is a sky conditions and astronomical events application developed by Mac Observatory (Andrew Burwell). We respect your privacy and have designed Transit to collect the minimum data necessary to function.
The short version: Transit does not create accounts, does not track you, does not use analytics, and does not sell or share your personal information. Astronomical calculations happen on your device, and the only personal data that ever leaves your Mac is your approximate location, sent to weather services to fetch your local forecast.
Data We Access
Location Data
What: Your approximate geographic coordinates
Why: Two purposes. First, on-device: rise, transit, and set times, altitudes, and satellite pass predictions are all location-dependent and computed locally. Second, to fetch your local weather and seeing forecast for the Conditions and Seeing scores.
Where it goes: Sent to Open-Meteo (api.open-meteo.com) for weather data and to 7Timer for the seeing forecast. Nowhere else.
Stored: Not stored permanently by Transit; queried fresh as needed
You can deny Location Services access and enter coordinates manually instead — useful for a fixed observing site. If you provide no location at all, weather-dependent features are unavailable, but the app still runs.
Open-Meteo's privacy policy: https://open-meteo.com/en/terms
Notifications
What: Event alerts (e.g., "Io is crossing Jupiter's limb")
Why: Core functionality — telling you when to look up
Where it goes: Nowhere. Notification content is generated on your device and delivered through macOS's local notification system.
Stored: Your notification preferences are stored locally on your Mac
Preferences
What: Your settings — tracked objects, alert gates, observing hours, menu bar layout, units
Why: So the app behaves the way you configured it
Where it goes: Nowhere. Stored locally in Transit's sandboxed preferences.
Stored: On your Mac, under your control
Data We Do NOT Collect
- Personal accounts or login information
- Analytics or usage tracking
- Advertising identifiers
- Crash reports (unless you choose to share via Apple)
- Contacts, calendars, or other personal data
Third-Party Services
Transit uses the following third-party data services:
| Service | Purpose | Data Sent |
|---|---|---|
| Open-Meteo | Weather data for the Conditions score | Approximate location (latitude/longitude) |
| 7Timer | Astronomical seeing forecast for the Seeing score | Approximate location (latitude/longitude) |
| CelesTrak | Satellite orbital elements (TLEs) for pass predictions | No personal data — requests identify which satellites to fetch, not you |
| Great Red Spot longitude source | Keeping GRS transit predictions current (values per JUPOS / Sky & Telescope) | No personal data |
Open-Meteo and 7Timer receive only coordinates so they can return a forecast for your area. The CelesTrak and Great Red Spot requests contain no information about you at all. We chose Open-Meteo specifically because it does not require user accounts or API keys and has a privacy-respecting approach. See their terms at https://open-meteo.com/en/terms
Data Storage and Security
- All astronomical calculations run on your device
- Weather and seeing data are held in memory and not persisted to disk
- Satellite orbital elements and the Great Red Spot longitude are cached locally so the app keeps working offline
- Transit is sandboxed per macOS security requirements
- We have no servers that receive or store your personal data
Children's Privacy
Transit does not knowingly collect any personal information from children under 13. The app does not require accounts or collect personal data beyond the location functionality described above.
Your Choices
- Location access: Can be granted or denied in System Settings → Privacy & Security → Location Services, or replaced with manual coordinates in Transit → Settings → General
- Notifications: Can be managed in System Settings → Notifications, or per-event inside Transit
- Background data refresh: Automatic refresh of satellite and Great Red Spot data can be disabled in Transit → Settings → Data & Accuracy (the app will use last-known data)
Changes to This Policy
If we make material changes to this privacy policy, we will update the "Last updated" date and, for significant changes, notify users through the app or our website.
Contact
For privacy questions or concerns:
Email: support@macobservatory.com
Website: macobservatory.com
Developer: Andrew Burwell, Mac Observatory
App Store Privacy Labels
For transparency, here is how we respond to Apple's App Store privacy questions:
Data Used to Track You: None
Data Linked to You: None
Data Not Linked to You: Coarse location (for weather and seeing forecasts only)
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