SOLAR and LUNAR ECLIPSES : Part 3
EARLY HISTORY of SOLAR and LUNAR ECLIPSES
Understanding the nature of observed eclipses was once fraught
with the combination of superstition, fear and seemingly possible
‘bad
omens’ augured down on humankind from
the immortal gods. The early ancient astronomers were unable to
correctly interpret the real causes of the eclipse, let alone predict
them.
Thales of Miletus (c.624-546 B.C.), an early Greek
philosopher was first to be accredited to be able to roughly predict
any observed solar or lunar eclipse. His best prediction was a total
solar eclipse, as was told by the historian Herodutus of
Halicarnassus (c.484-525 B.C.), was importantly instrumental in
finally ending the six year war at the Battle of Halys (28 May 584
BCE.) between the Asia Minor Lydians and the invading middle-eastern
Median Empire (Medes.) (Some sources say 585 BC., but the date and
protracted path is given in the
Five
Millennium Canon of Solar Eclipses.) It seems that both sides
saw the eclipse in the late afternoon as a bad omen, and they laid
down their arms as to not anger either
side’s gods. Immediately after the
battle an armistice was declared and a new treaty was enacted. From
this solar eclipse this battle is one of the first historical dates
we currently know with some certainty, as past eclipses be easily
dated into the ancient distant past. The story may also be anecdotal
for other reasons not passed down to us in the present day.
Later in about 455 B.C., the Greek philosopher, Anaxagoras
of Clazomenæ (c.500-429BC.) certainly knew the correct
explanation, because he realised that the round shape of the lunar
eclipse shadow was the spherical shape of the Earth projected into
space. By 150 BC., the “Father of
Astronomy” astronomer,
Hipparchus of Rhodes (Hipparchos) (c.190-120 BC.) had first
correctly describe the nature and causes of all types of
eclipses.
Others may have understood this fully, or only
partly, but unfortunately most of these earliest records have been
either destroyed or are now lost to us forever.
The oldest known written solar eclipse, at least with any
certainty, was made from the city of Ugarit in Mesopotamia on 3rd May
1375 BC. The oldest recorded lunar eclipse we have at the moment was
in 1136 B.C., just before the time of the Trojan Wars between
isolated states of Greece and Asia Minor.
Various solar eclipses were often recorded in the ancient
literature. These can be divided into several different types, as
first employed by Robert R. Newton in 1969. (Geophys.,
J.RAS., 14, pg.505-539 (1968)) Such eclipses are
importance as they can set precise dates for the ancient historical
events that occurred around some important period or war. Historical
astronomers have made detailed studies of the ancient records,
sometimes called archeoastronomy, for precisely this reason.
Sadly we know very little about the circumstances of these early
eclipses because of the poorly presented and often nondescript text
that has been passed down to us.
Magical eclipses have been purely fabricated to
meet some significant event or war in history. An example was the
solar eclipse of 2nd October 480 BC., when the march of the Persia
king Xerxes on Boeotia in Greece was suddenly turned back because of
the occurrence of an eclipse, though some have interpreted this as
the reason for the beginning of the invasion of Greece. Another was
the solar eclipse reported by the poet Archilochus of Paros
(680-645 BC.) that presumably occurred on 6th April 648 BC., over the
Aegean island of Thasos near the Macedonian coast.
Assimilated eclipses are ones thought to have
been date shifted purposely by the author to meet certain political
events or wars of particular significance. We think that some of the
famous battles were staged around the time of some eclipse, whose
only reason was to frighten off the opposing side. Both the Greeks
and Romans may have used this idea to their own advantages. Probably,
the most famous example was during Alexander the Great in his final
Battle of Issus against the Persian army on 26th September 331 BC.
Fighting in this battle was the morning after a total lunar eclipse.
Alexander claimed to his men that it meant good fortune. The Persians
shrank in fear and terror, interpreting this as a sign of a coming
defeat. Historians have often said that this may have been the story
created after the battle to show that the gods were actually on the
side of the Greeks.
Literary eclipses are ones that are pure
fiction, created solely for the prestige of the author. An example is
the presumed observed eclipse was during 71 AD. in Italy. It never
happened!
SAROS and PREDICTING ECLIPSES
True eclipses are ones that occur on the dates that can be
pre-calculated. An example was the solar eclipse that occurred in
Thebes on 13th July 364 B.C. The main significance of this eclipse
was that it changed the mind of king Alexander of Pheræ, so that
he decided to attack the city of Thessaly — in the northern
Greece independent state of Thiazole. (However, R. Newton has
recently stated some doubt in this eclipse, as five other eclipses
are also possible.)
One of the first means of predicting eclipses was the discovery of
the Saros Cycle or Saros, which was discovered, by
unknown means, by the Greeks and Chaldaeans. In the 5th Century BC,
the Greek astronomer Anaxagoras announced that he could predict
eclipses using the Saros Cycle, but the Athenians at the time
considered this blasphemous against the gods and rejected the whole
idea out of hand. He was later proven to be right. Yet some
historians currently believe the ancient discovery of the Saros might
be just coincidence.
Today, the Saros refers to the period between successive eclipses
whose predictable pattern recurs in periods of about 6585.32 days or
18 years 10 days and 8 hours, and corresponds to exactly 223
successive lunar orbits or so-called lunations. We know that the
Saros is caused by the lunar inclination to the ecliptic — the
plane that the planets follow. When the lunar position crosses the
elliptical plane, it varies or precesses during every Saros, and
eventually after the period returns to the same starting point when
it again crossed the ecliptic. In addition, eclipses are related to
the eclipse year, based on the
“draconic
month” of the Moon, when the Sun
coincides to the Moon’s ascending node.
Successive eclipses each Saros cycle occurs one-third further around
the Earth’s circumference, adding the
eight extra hours, and therefore, once every 54 years 31 days,
another similar eclipse will roughly occur near the same place of the
previous eclipse.
Example of the Saros Solar Eclipses
ECLIPSES in SAROS
No.139 |
Eclipse Date |
Duration Totality |
Location |
18th March 1988 |
03m 36s |
Indonesia, Northern Pacific |
29th March 2006 |
04m 07s |
Africa, Western Europe |
08th April 2024 |
04m 28s |
Mexico, Southern North America |
20th April 2042 |
04m 51s |
China, Japan, S.E. Asia |
30th April 2060 |
05m 15s |
Northern Africa, Turkey |
11th May 2078 |
05m 40s |
Mexico, Southern North America |
22nd May 2096 |
06m 06s |
Indonesia, Northern Pacific |
03rd June 2114 |
06m 32s |
Northern Africa, Turkey |
Details of a Saros
ECLIPSES in SAROS
No.139 |
Place In Saros |
Date |
Eclipse Type |
Duration |
Location |
First Eclipse |
17th May 1501 |
Partial |
-- |
North Pole |
First Eclipse |
17th May 1627 |
Hybrid |
00m 00s |
North |
Longest Eclipse |
11th August 2186 |
Total |
07m 29s |
N.South America |
Last Eclipse |
16th July 2601 |
Hybrid |
00m 35s |
South |
Last Eclipse |
03rd July 2763 |
Partial |
-- |
South Pole |
Within Saros 139,
there are;
In all there are 71 Eclipses, being;
6 Partial, 0 Annular, 43 Total and
12 Hybrid
Saros 139 lasts over 1262.11 years
Reference :
Fred
Espanak Eclipse Web Site |
Important Disclaimer
The user applying this data for any purpose forgoes
any liability against the author. None of the information should be
used for either legal or medical purposes. Although the data is
accurate as possible some errors might be present. The onus of its
use is placed solely with the user.
Last Update : 26th November 2012
Southern Astronomical Delights ©
(2012)
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