Eclipse Canon Comparison
Solar and lunar eclipse predictions vs. the NASA Eclipse Catalog.
Eclipse Catalog Comparison
This report compares Moira's eclipse calculations against the local NASA catalog fixture already used in the test suite. It is intended as a readable cross-era summary, not as a replacement for the tests themselves.
Maxima Snapshots
Solar
| NASA date | NASA type | Moira native type at NASA maximum | Notes |
|---|---|---|---|
| -1797-02-01T21:25:34 | H | hybrid | classification at catalog maximum |
| 0500-02-15T11:06:27 | H | hybrid | classification at catalog maximum |
| 0500-08-11T00:35:02 | A | annular | classification at catalog maximum |
| 2005-04-08T20:36:51 | H | hybrid | classification at catalog maximum |
| 2809-02-05T21:20:58 | H | hybrid | classification at catalog maximum |
Lunar
| NASA date | NASA type | Moira native type at NASA maximum | Notes |
|---|---|---|---|
| -1801-04-30T07:38:52 | T | total | classification at catalog maximum |
| -1801-10-23T22:49:56 | P | partial | classification at catalog maximum |
| 0499-03-13T12:12:02 | T | total | classification at catalog maximum |
| 2000-01-21T04:44:34 | T | total | classification at catalog maximum |
| 2800-02-01T23:47:11 | T | total | classification at catalog maximum |
Search Timing
These are the more meaningful comparison rows, because they compare the catalog's reported greatest-eclipse instant against Moira's own searched maximum.
Solar Search Cases
| Case | NASA expected | Moira native | Residual |
|---|---|---|---|
| ancient_hybrid (hybrid) | -1797-02-01T09:51:13.000029Z | -1797-02-01T09:49:52.939670Z | -80.06 s |
Lunar Search Cases
| Case | NASA expected | Moira native | Native residual | nasa_compat | Compat residual |
|---|---|---|---|---|---|
| ancient_total (total) | -1801-04-29T20:03:04.999996Z | -1801-04-29T20:02:15.346372Z | -49.65 s | -1801-04-29T20:08:07.632251Z | +302.63 s |
| future_penumbral (penumbral) | 2801-06-17T19:00:54.999930Z | 2801-06-17T19:01:15.757170Z | +20.76 s | 2801-06-17T19:01:25.031833Z | +30.03 s |
Interpretation
- At catalog maxima, Moira's native classifier agrees cleanly across the representative ancient, classical, modern, and future rows in this local fixture slice.
- The meaningful timing differences appear in searched greatest-eclipse instants, not in simple at-instant classification.
- For lunar ancient cases, the largest single contributor is the Delta T branch choice. In the diagnosed
ancient_totalcase, switching the same native shadow-axis objective from native Delta T to NASA-canon Delta T moves the answer by about 387 seconds. - Moon treatment matters too. In that same case, switching from a retarded Moon to a geometric Moon inside the native branch moves the result by about 35 seconds.
- Once Delta T branch and Moon treatment are aligned, Moira's native shadow-axis minimum and the canon gamma-minimum objective collapse to essentially the same instant. That means the remaining difference is primarily model basis, not an unstable search algorithm.
- Practical reading: modern and near-modern comparisons are tight; deep ancient and far-future timing comparisons should be read through the lens of Delta T doctrine and event-definition choice, not just raw residual size.