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Public Universe

Moon, planets and catalogue targets

Plan a night

Find geometric observing windows for your location. Clouds, terrain, brightness and equipment can still prevent a useful view.

A night runs from local noon to the following noon. Times include their UTC offset so clock changes are unambiguous. Coordinates are rounded to two decimal places and sent for this calculation; this form does not save them.

Not sure what to choose? Find an explained shortlist for your site and equipment.

Location, time and targets

Observing hours (optional)

Leave both times blank to consider the whole local night. Otherwise enter UTC start and end times within that night; UTC avoids ambiguous clock-change hours.

Enter 2–72 lines, each with an azimuth and minimum altitude in degrees, separated by a space. North is 0°, east 90°, south 180°, west 270°. Heights interpolate between directions and across north; the larger of this profile and your minimum altitude applies. Blank means terrain is unknown.

Targets

Choose at most eight targets in total. Use exact, case-sensitive identifiers from the starter catalogue, separated by spaces or commas. Only records with supported coordinate metadata can be calculated; the catalogue is a bounded sample.

Moon separation applies to other targets only while the Moon’s geometric centre is above 0°, independent of your terrain profile. Every target must remain at least 30° from the Sun. This is a night-planning tool and provides no solar-observing instructions.

A full calculation may take up to 40 seconds. No account is required.