Messier Sweep is a planner and logbook for the Messier marathon. If something isn't working, or you have a question about the star‑hop guides, the planner or your logbook, send us a note below.
Open the Planner tab, set your latitude (typed in or from your location), pick a night from the list, and tap "Plan my marathon for this night." That replaces the sample sweep with a real one for your site and date. You can also remove the sample from Settings at any time.
Some Messier objects are only above the horizon in a dark enough sky for part of the night at your latitude. If an object sets or fades into twilight before you reach it in the sequence, the app marks the time it was lost so you know when to move on.
No. Every calculation — twilight times, moon phase, object visibility — runs on your device. The app has no account and does not need a network connection to work.
Open a marathon in the Log tab and use the share icon to export a summary through the system share sheet as text and an image.