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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.

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

Important findings have resulted from the analysis of over 12,000 crater timings reported by astronomers throughout the world, and recently these new data have been supplemented by image analysis of video records made of lunar eclipses recorded in Western Europe, South America and in Australia.

The most 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 thought 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 this recent 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 a CCD video 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 first 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.

This is in all probability due to the curvature of the Moon's surface and perhaps slight changes in the umbra size throughout the lunar eclipse. Further research is required.

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, or e-mail now at: minnah@netspeed.com.au