Does SolarEclipse only cover a limited date range?

Question

If I use the example from the documentation for SolarEclipse and simply replace the years there with older ones, say from around Shakespeare's time,

startYear = 1575; endYear = 1614;
GeoGraphics[{GeoStyling[None],Opacity[.3],Red,
             SolarEclipse[{DateObject[{startYear,1,1,0,0}],
                           DateObject[{endYear,12,31,0,0}],All},
            "PartialPhasePolygon"]},
            GeoProjection->"Equirectangular"]

I'm unable to plot anything and get repeated errors:

Missing is not a graphics primitive or directive

Is "TotalPhasePolygon" available for only a limited range of dates. If so what dates and where is that documented?

Answer 1

When this data was originally curated, NASA was providing polygon data for a subset of the eclipses in their catalog.

Since then, NASA has changed their site, and they now give the Besselian Elements for every eclipse. Here are the elements for an eclipse from 798 BC.

Since it's possible to compute the relevant paths from these elements, we would definitely like to improve our coverage for historic eclipses.

To find out which eclipses have polygons, it is necessary to grab all the data and filter out the missing elements

data = Thread[
   {SolarEclipse[{DateObject[{-500, 1, 1, 0, 0}], Today, All}, 
     "MaximumEclipseDate"],
     SolarEclipse[{DateObject[{-500, 1, 1, 0, 0}], Today, All}, 
     "TotalPhasePolygon"]
    }
   ];

Length@data
(* 1255 *)

Length@DeleteCases[data, {_, _Missing}]
(* 96 *)

First @ DeleteCases[data, {_, _Missing}]

So the earliest eclipse we have polygons for is in 1654.