Meteor radiant observing geometry
Compare radiant height, astronomical darkness and Moon height during a 24-hour observing window using coordinates from a current shower notice.
Your inputs
Start with the example values, then replace them with your own. For tables, keep the vertical bar separators and use a dot for decimals.
This simplified educational calculation has stated assumptions. Do not use it for navigation, engineering safety or other safety-critical decisions.
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Result and workspace
Use the start button to open your result or activity.
How it works
At hourly UTC samples, transform the fixed entered radiant and calculate Sun and Moon altitudes. Flag samples with Sun below −18 degrees and radiant above the horizon. Radiant drift, cloud, limiting magnitude and shower activity are excluded; no meteor count is promised.
Worked example
These sample results use the original example inputs in the form. They do not change when you edit your inputs; your own result appears in the workspace.
| UTC instant | Radiant altitude | Sun altitude | Moon altitude | Geometry |
|---|---|---|---|---|
| 2026-10-08T00:00:00.000Z | 72.946 | -44.3108 | -16.4128 | Dark and radiant above horizon |
| 2026-10-08T01:00:00.000Z | 71.2003 | -34.9115 | -6.1312 | Dark and radiant above horizon |
| 2026-10-08T02:00:00.000Z | 65.5824 | -24.263 | 4.1313 | Dark and radiant above horizon |
| 2026-10-08T03:00:00.000Z | 58.2358 | -13.0342 | 14.8117 | Outside selected geometry |
Read the result carefully
Results depend on the values and assumptions shown above. Change one input at a time to see its effect. A blank or unavailable result means the data does not support a calculation; it is not zero.