Meteor Shower Observing Planner
Compare observing windows near ten major 2027 meteor-shower peaks using local darkness, Moon position and radiant altitude.
Starts with an editable example. Replace the dates and rules with your own.
Your calculation
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Choose your dates.
Select your counting rules and calculate.
Calculation details
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How to use this calculator
Choose a shower or all ten, the evenings around its listed peak, your location, darkness threshold, Moon rule and minimum window.
Annual peak dates and radiants come from the IMO 2027 calendar. Peak dates are approximate; the radiant is held fixed over nearby nights. Windows rank by duration and do not predict meteor counts or weather.
A worked example
The 2027 Perseid reference peak is August 13. Search nearby evenings to compare local darkness and Moon-free opportunities.
Why can I only choose 2027?
Shower predictions need annual review. This version deliberately covers the published 2027 table and does not extrapolate its dates to later years.
Further reading: IMO 2027 meteor-shower calendar. Your entered rules determine this result.
Which calendar and years are supported?
Gregorian input coverage is 1900-2100 unless the method states a narrower range. Results explain calendar conventions and local date boundaries. Astronomy uses a level horizon at sea level. CSV, print and copy retain the result rules; calendar files contain only calculated events. Nothing is scheduled automatically.
What happens to my dates?
Calculations run on your device. Saving a calculation is optional and keeps it in this browser. A setup link contains the dates and settings you entered; anyone with the link can read them. Use one tab per saved calculator. Clear saved data from Privacy & settings.