Observing Night Planner
Plan a night of stargazing. Compare target heights, dark hours and distance from the Moon, then export your observing windows.
When will my astronomy targets be visible tonight?
Enter fixed ICRS target coordinates or select the Moon and planets in the target CSV. Choose the local observing date, IANA time zone and WGS84 location. Set minimum target altitude, maximum Sun altitude, Moon separation and minimum window duration. The report covers local noon to the following noon, accounts for clock changes and exports qualifying windows, sampled positions, a chart and UTC calendar events.
Your result
A little clarity, right here.
Start with your own content or load the example. Your result will appear here.
Three simple steps
How to use Observing Night Planner
For each target, enter a Moon/planet name in the body column, or leave body blank and enter fixed ICRS RA and declination.
Choose the observing date, time zone, site and visibility constraints. Check whether Moon separation should apply below the horizon.
Review local windows and the altitude chart, then download the full report, positions and calendar events.
Common questions
Good to know
Understand the result.
Keep the original.
Is this tool free, and are my files uploaded?
This tool is free with no account required. When you run the tool, your input goes to a separate processing service. Temporary files are deleted when the job ends. You can download the result to your device.
What are the limits and details?
Up to twelve uniquely named targets and 10,000 input characters for one local-noon interval within 1900–2050 UTC. RA uses decimal hours from 0 to below 24; declination uses degrees from −90 to 90. Custom coordinates omit proper motion and parallax. A one-minute event search refines detected boundaries to about one second; sub-minute windows can be missed. This resolution is not an accuracy guarantee. Peaks use the selected sample interval. The Moon target bypasses the Moon-separation filter. No clouds, seeing or terrain prediction. Uses fixed NASA/JPL DE421 or DE440s data and Skyfield 1.55 bundled time tables, without runtime downloads. Sun, Moon, Mercury and Venus use body centers; Mars through Pluto use system barycenters. Positions include light travel time, aberration and gravitational deflection. Altitudes exclude refraction, terrain, weather and polar motion. Historical and future Earth-rotation uncertainty limits timing accuracy. Jobs stop after two minutes.