AtlasSkyLog

AtlasSkyLog is an observing notebook for anyone who owns binoculars and keeps meaning to write things down. It answers two questions. What is worth going outside for tonight, and what did I see last time? TONIGHT, WORKED OUT FOR YOUR LATITUDE Sunset, civil, nautical and astronomical twilight, and the observing window between the end of dusk and the start of dawn. If your latitude gets no real darkness at this time of year, the app says so plainly and falls back down the ladder rather than printing a time that does not exist. The moon is drawn at its actual phase — the terminator is a projected ellipse, not two overlapping circles, so a gibbous moon looks gibbous — with a verdict on what its light means for faint targets tonight. WHAT IS ACTUALLY UP Forty well-known targets: the Andromeda and Whirlpool galaxies, Orion and the Lagoon, the Hercules and Wild Duck clusters, the Ring and the Dumbbell, Albireo and Mizar. The app sweeps the whole catalogue across tonight's window and lists what clears 20 degrees, highest first, with the time each one peaks. Open any of them for its coordinates, how high it ever gets from your site, and a plotted curve of its altitude across the night with the peak marked. YOUR SITE, TYPED NOT SENSED Pick a preset city or type a latitude and longitude. The app requests no location permission, because being able to compute a sunset is not a good enough reason to be able to follow someone around. WRITE IT DOWN Log what you saw, when, through what, and how the sky was — seeing and transparency rated separately, because a night can be steady and murky or crisp and turbulent. Search the log, star the good nights, and see every past sighting of an object on its own page. NIGHT VISION THAT MEANS IT The red mode is a second theme, not a filter laid over the first one. Every colour in the interface is replaced, so nothing but deep red reaches your eye and a glance at the phone does not cost you twenty minutes of dark adaptation. NINE BADGES AND A YEAR OF CHARTS Sightings per month, what kinds of object you gravitate towards, the faintest magnitude you have reached. Badges are recalculated from the log whenever it changes, so they can never disagree with what you actually wrote down. EVERYTHING STAYS HERE No account, no sync, no analytics, no advertising, no crash reporting and no in-app purchases. No location permission and no internet permission — the app cannot open a connection, which is exactly what you want in a field with no signal. Your log lives on your phone, and uninstalling takes it with you. All the astronomy runs on the device from standard low-precision formulae, accurate to a minute or two on rise and set times. Good enough to plan an evening; not intended for navigation.