Eclipse

1
Eclipse!
A Presentation to Astronomy Ireland By David
Grennan, 27th February 2006
2
Solar Eclipses - Past, Present, and Future.
Eclipse Mythology Chinese, Hindu, Egyptian,
Impact on modern day science and religion.
Mechanics of Solar Eclipses Why eclipses
occur. Types of Eclipse. Phases of an
eclipse. Shadows  Bailys Beads. Diamond
Ring. Temperature Corona. Prominences.
3
Solar Eclipses - Past, Present, and Future.
Safely Viewing Eclipses
Eclipse, March 29, 2006 a guide. Using computer
simulations Eclipse from Ireland. Eclipse from
Turkey. Eclipse from Space
Future Eclipses Important Eclipses present
2030 The 'almost' total eclipse of 2015 from
Ireland.
4
Eclipse Lore and Mythology
"Nothing there is beyond hope, nothing that can
be sworn impossible, nothing wonderful, since
Zeus, father of the Olympians, made night from
mid-day, hiding the light of the shining Sun, and
sore fear came upon men." Archilochus (c.710 -
676 BC)
5
Eclipse Lore and Mythology
Our ancestors saw eclipses as evil omens, often
as portents of some catastrophic event or a sign
from their deities.
The earliest recorded eclipse was in China on
October 22, 2134 BC. The two court astrologers
to the Emporer lost their heads because, they had
failed to predict it
The Babylonians were the first to calculate the
regular intervals at which eclipses occur. Thales
of Miletus predicted a solar eclipse that
marked the beginning of the Greek
scientific/philosophic era.
6
Eclipse Lore and Mythology
Word eclipse comes from a Greek word,
ekleipsis meaning abandonment.
There is a story that suggests Christopher
Columbus used his Knowledge of an upcoming lunar
eclipse to great effect.
7
Ancient China
People of ancient China were convinced that
eclipses Occurred because a great dragon (or
toad, or dog) was Devouring the Sun. They made
load noises, banged implements etc to scare Away
the dragon. As total eclipses can only last a
maximum of 7 ½ minutes There raucous behaviour
always had the desired effect.
8
Ancient China
Han Dynasty (206 BC - 220 AD)
9
Hindu Folklore
According to Hindu mythology, the eclipse
represents the demons Rahu and Keta locked in
celestial combat and eating the Sun.
10
Hindu Folklore
The Gods were drinking the elixir of
immortality. The demon Rahu slipped into their
midst and stole a sip. Surya (the sun) and Soma
(the moon) reported the incident to the great
deity Vishnu. Vishnu promptly sought out the
impudent Rahu and lopped off his head. But having
become deathless, Rahu survived and to this
day seeks revenge on the tattletales by devouring
them.
11
Ancient Egypt
The egyptian word for eclipse is Akhet King
Akhenaten (1356-1338 BC) built his capital
according to the totality path of the solar
eclipse of 08/15/-1351. The Pharaoh named his new
residence 'Akhet Aten'. The name of the city
means 'The Eclipse of Aten'. The name of the
Giza Sphinx was 'Hor in the Akhet Many
different ancient egyptian sun cults saw
eclipses Differently. Many refer to a serpent
eating the Sun God. Most however refer to a great
hawk stealing RAs glory.
12
Eclipses and Religion
Many hindus to this day immerse themselves in
holy rivers And lakes during solar
eclipses. Working during eclipses is considered
bad luck. Muslim tradition holds that the
prophet Mohammed, the founder of Islam, prayed
for the duration of an eclipse. Senior muslim
clerics issued an edict forbidding people to look
at the Sun directly because it transgresses
Islamic law to harm oneself. Druids believe
eclipse represents man and woman together.
13
Eclipses and Religion
Luke 2344-48 And it was about the sixth hour,
and there was a darkness over all the earth until
the ninth hour. And the sun was darkened, and
the veil of the temple was rent in the
midst. Some suggest a solar eclipse as an
explaination for The darkness however the facts
dont lend credance.
14
Mechanics of Solar Eclipses
Solar eclipse of 11 Aug 1999 From
MIR Spacestation.
15
Mechanics of Solar Eclipses
Todo insert flash file.
16
Partial Eclipse
17
Annular Eclipse
18
Total Eclipse
Although a total eclipse refers to a specific
event, the events leading Up to totality and
following it also hold much interest.

• Partial Phase
• Shadows
• Bailys Beads
• Diamond Ring
• Totality

19
Partial Phase
During the partial phase there are many
interesting things to note.

• First Contact.
• Eclipse increasing in magnitude.
• Temperature.
• Increasing Darkness
• Shadow Bands
• Crescent Shadows
• Creatures settling believing night is imminent
• Moons shadow racing from the west(ish).
• Bailys Beads
• Diamond Ring

20
First Contact.
The moment when the western limb of the Moon
contacts the Eastern limb of the Sun.
First contact is not directly Visible, however
very shortly Afterwards a little bite is Taken
from the Sun.
21
Temperature
As the eclipse increases in magnitude, the amount
of warming Sunlight reaching us falls. As the
eclipse reaches 70-80 you will begin to feel a
noticeable Coolness as if night were coming.
22
Increasing Darkness
With the decrease in the area of Sun presented to
us Ambient light levels fall. Most noticeable in
the latter stages of the eclipse. Video from
west Africa showing this dramatically.
23
Shadow Bands
Caused by distortions in the Earths atmosphere
and the partially Eclipsed Sun.
Best seen on a pale coloured Wall or concrete
pavement.
24
Crescent Shadows
Note shadows cast by irregularly shaped objects
such as leaves From trees.
25
Crescent Shadows
26
Bailys Beads.
At this point the only sunlight reaching us is
through the undulating Valleys on the Moons limb.
27
Bailys Beads.
28
Diamond Ring
The chromosphere is visible and the Corona is
becoming visible. The very last of Bailys Beads
is also visible. Totality is now imminent!!!!!!
29
Totality!!!!
30
Totality!!!!
31
The Hybrid Eclipse.
The official explaination!
A hybrid eclipse is a unique type of central
eclipse where parts of the path are annular while
other parts are total. This duality comes about
when the vertex of the Moon's umbral shadow
pierces Earth's surface at some points, but falls
short of the planet along other portions of the
eclipse path. The curvature of Earth's surface
brings some geographic locations along the path
into the umbra while other positions are more
distant and enter the antumbral rather than
umbral shadow.
Fred Espenak
32
The Hybrid Eclipse.
In practice!
33
Safely Viewing Eclipses
34
Eclipse Safety
Directly looking at the Sun, even for a short
time, CAN PERMANENTLY DAMAGE YOU EYESIGHT
35
Eclipse Safety
Approved solar filter material Should be used to
cover your Equipment and your eyes AT ALL TIMES.
36
Sunglasses

• You should choose sunglasses that
• reduce glare
• filter out 99-100 of UV rays
• protect your eyes
• are comfortable to wear
• do not distort colors.

Source Prevent Blindness America.
37
How to use Filter Material
38
How to use Filter Material
39
How to use Filter Material
40
Eclipse of March 29th 2006 . We will use
computer simulations to look at this Eclipse from
different vantage points Animations created with
Starry Night Pro Plus Software.
41
Important Solar Eclipses Present - 2030
42
(No Transcript)
43
(No Transcript)
44
(No Transcript)
45
(No Transcript)
46
(No Transcript)
47
(No Transcript)
48
(No Transcript)
49
(No Transcript)