An almanac by day · a red deck at night
Telescope Log: Darksite.
Know what's worth observing tonight — with your telescope. A private, offline observing companion that plans your night around your own gear, logs what you see, and keeps every record on your device.
Get Darksite
iPhone · iPad · Mac · Android · Windows — in store review now
Planned around your gear, not a generic list
What should I observe tonight?
Darksite reads the night — astronomical dark, the moon, cloud & conditions and space weather — then picks targets that actually fit your telescope and eyepieces. Each pick reads in plain language, never an opaque score: when it peaks, how high it climbs, whether it frames in your field, and how far the moon sits from it.
The same screen · red field on
One white flash costs you 30 minutes
A genuine red-lit instrument at the eyepiece.
At the scope, every Darksite screen renders deep red on near-black with a brightness floor — no white flash on any screen, ever. A custom red keyboard, big-step steppers and voice-first capture mean you log an observation without ever reaching for a phone that blinds you. It's the whole app, night-vision safe.
Plan indoors, observe outside
The desk view and the field view, one log.
On Mac and Windows, Darksite opens into a wide planning desk — the almanac, your queue and the full log side by side. On iPhone and Android it folds down to a one-handed red deck you can work at the eyepiece. Same app, same records, no account tying them together.
What's inside
Built for how you actually observe.
Gear-aware picks
Add your telescopes, eyepieces and filters once. Darksite does the field-of-view and exit-pupil math and only suggests what your setup can actually show, framed in the eyepiece you'd reach for.
Sketches & voice
Log every session with a round eyepiece-view sketch field, seeing and transparency scale, NELM and SQM, and a voice clip captured at the scope — all red-safe, all on your device.
Work your programs
Track Messier, Herschel and Lunar observing programs as a completion matrix toward the certificate, with coordinator-ready exports when you're ready to submit your work.
Night vision, kept
A first-class red-on-black mode with a brightness floor and a custom in-field keyboard — no white flash on any Darksite screen, so your dark adaptation survives the whole session.
Know the night
Cloud & conditions, transparency and seeing, geomagnetic activity for aurora watchers, and visible ISS passes for your site — the context that decides whether tonight is worth setting up.
Private & offline
No account, no ads. Your gear, logs, sites and lists live on your device, and your observing coordinates never leave it. Backup, restore and export are free, forever.
Simple, honest
Free to observe. One purchase to go unlimited.
Free
- The gear-aware Tonight planner
- Observing log with a sketch per session
- Cloud & conditions, space weather & ISS passes
- Red field night-vision mode
- Backup, restore & export — always free
Darksite Pro
- The full observing-programs library
- Coordinator-ready validated exports
- Week-ahead planning
- Sketch canvas & multiple photos per observation
- Advanced statistics
Pay once. No subscription. Ever.