|
Solar Eclipse
|
Due to tidal acceleration, the orbit of the Moon around the Earth becomes approximately 3.8 cm more distant each year. It is estimated that in slightly less than 1.4 billion years, the distance from the Earth to the Moon will have increased by 23,500 km. In the same timeframe, the Sun will increase in size, meaning that the Moon will no longer be able to completely cover the Sun's disk. This will be true even when the Moon is at perigee, and the Earth at aphelion. Therefore, the last total solar eclipse on Earth will occur in slightly less than 1.4 billion years.
Historical eclipses
Historical eclipses are a very valuable resource for historians, in that they allow a few historical events to be dated precisely, from which other dates and ancient calendars may be deduced. A solar eclipse of June 15, 763 BC mentioned in an Assyrian text is important for the Chronology of the Ancient Orient. There have been other claims to date earlier eclipses. The Emperor Zhong Kang supposedly beheaded two astronomers, Hsi and Ho, who failed to predict an eclipse 4000 years ago. Perhaps the earliest still-unproven claim is that of archaeologist Bruce Masse, who putatively links an eclipse that occurred on May 10, 2807 BC with a possible meteor impact in the Indian Ocean on the basis of several ancient flood myths that mention a total solar eclipse.
|
|