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About these Pages

These pages have been prepared and maintained by Byron W. Soulsby, a research amateur astronomer who operates the Isabella Plains Lunar Observatory in Canberra the Australian Capital Territory, situated in the south-east of mainland Australia.

The lunar eclipse information is generated by a suite of exclusive software programs first prepared in 1984 in Microsoft GW Basic and developed to run on the Macintosh computer under Microsoft QuickBasic. These programs are now available for download for Windows XP execution.

The lunar eclipse ephemerides are based on initial data obtained from the Astronomical Almanac and/or from the US Naval Observatory Interactive Computer Ephemeris software (also available for download); particularly applicable for analysis of historical lunar eclipses where data is not available from the Almanac. The daily polynomial coefficients of the Moon are obtained from WINOCCULT by David Herald.

Research papers have been published in the Journal of the British Astronomical Association, the Australian Journal of Astronomy and in the Publications of the Astronomical Society of Australia.

Important findings have resulted from the analysis of over 13,000 crater timings reported by astronomers throughout the world, and recently this data has been supplemented by image analysis of video records and still images of lunar eclipses recorded in Western Europe, South America, the Netherlands, France, Sweden, Turkey and in Australia.

One important finding is that the oblateness of the umbral shadow cast onto the Moon from the upper atmosphere of the Earth is three times that previously thought by classical astronomy. The out-of-roundness, (or the oblateness, eccentricity or ellipticity) of the Earth's atmosphere was taken to be equal to the shape of the solid Earth, or its Geoid - a value of 1 in 298.27. Now it has been shown from my lunar eclipse research, that this value is 1 in 102, that is 3 times greater than that for the Geoid.

Computer analysis of images taken by video and still camera, show that the geometry of the Earth's upper atmosphere changes during each lunar eclipse such that the recorded diameter is smaller when the Earth's shadow covers the Moon's edge at first primary contact, increases at mid-eclipse and again reduces in size when the umbra begins to leave the Moon at fourth primary contact. The study has now been extended to include the computation of topocentric values of the penumbra and umbra as well as their measurement.  A comparison of the computed and measured values can be seen here.

These characteristics are due to the curvature of the Moon's surface and perhaps slight change in the size of the shadow throughout each lunar eclipse.  Research is continuing.


You could participate in this research concerning the geometry of the upper atmosphere of the Earth -- just go to the Lunar Eclipse Observer Home Page, or for further details e-mail me now at: minnah@netspeed.com.au