DR. NITIN GHATPANDE

The seminar presentation is based on a brief study of two technical reports by NASA, viz 1) NASA/TP–2009–214172, “Five Millennium Canon of Lunar Eclipses”, 2) NASA/TP–2006–214141 “Five Millennium Canon of Solar Eclipses” by Fred Espenak, NASA Goddard Space Flight Center, Greenbelt, Maryland & Jean Meeus (Retired) Kortenberg, Belgium. It covers fundamental aspects and various technical details of Lunar and Solar Eclipses from 2000 BC to 3000 AD (5000 years). The talk covers a brief history and chronology of the extensive work carried out about the Lunar and Solar Eclipses from the 19th Century onwards. The referred work achieves a prediction accuracy of < 1/40 seconds in the timings of various eclipse parameters over a span of 5000 years. This requires a highly accurate data related to the Sun & Moon, Longitude and Latitude, and the Earth-Moon Distance parameters. The lecture covers about the very high accuracies of these parameters related to the Sun, Moon and the Earth. In the background, the eclipse timings and orbital geometry details for various spacecrafts is covered. The Ecliptic plane, geometrical details of the Earth’s Umbra/Penumbra shadow near Moon, etc are also explained. Relevant details of the Moon’s orbit like Sidereal Period, Lunation (synodic period), Anomalistic period, Draconic period is explained. The relationship between, Full Moon Longitude and the Longitude of the Ascending/Descending Node for eclipse occurrence is covered. Various types of eclipses are covered with examples. Repeatability of Eclipse occurrence is explained. The condition to get similar Eclipses is explained, furthermore leading to the “Saros-Cycle” and “Saros-Series”. Some important statistics of past and future eclipses is also covered. The above papers are available on eclipse.gsfc.nasa.gov.in