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TOTAL SOLAR ECLIPSE CAIRNS 2012 Few people who witness a total eclipse of the Sun, fail to be deeply moved by the experience. Afterwards, they search for superlatives. Phrases such as, "the most spectacular thing I've ever seen" or "mother natures great show," flow from the lips of "eclipse chasers."
A total eclipse will be visible from Cairns beginning just after sunrise on 14th November 2012. Why not combine the experience of this great spectacle of nature with a visit to a hot spot for some of Australia's iconic attractions? A total solar eclipse occurs when the Moon passes between the Sun and the Earth. Total solar eclipses can only occur at some New Moon's but they don't occur every New Moon because the Moon's orbit is inclined 6o to the Earth's orbital plane. Eclipses only occur when the Moon passes through the Earth's orbital plane at New Moon otherwise the shadow misses the Earth(as illustrated in the diagram below).
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Eclipses on the Australian
Continent
Many people think
they've seen a total solar eclipse when in fact they've seen
a partial eclipse. Partial solar eclipses can be seen from a
very wide geographic area. Most adults in Australia will have
been able to see a partial solar eclipse at some point during
their lives but total solar eclipses must be viewed from within
a relatively narrow path defined by the Moon's traveling shadow.
Total eclipses occur on average about once every 18 months. Because
most of the Earth's surface is either ocean or remote desert
or wilderness, you usually have to go to a lot of trouble to
see one. From one fixed location, a total solar eclipse can be
seen about once every four hundred years. Over the past eighty
years only three total eclipses have been visible from the Australian
continent. A total eclipse in 1974, could only be seen from southwest
W.A. near Albany. The most widely seen event was in October 1976
when the Coorong, Mt Gambier, most of southern Victoria and the
southeast corner of NSW saw a total eclipse. The bigger towns
included Mt Gambier, Bendigo, Ballarat, Geelong, Melbourne and
Bombala among many others. In December 2002, a total eclipse
was visible inside a narrow 20km wide path over very remote areas
of South Australia between Ceduna and Cameron Corner. After the
2012 Cairns eclipse, the next opportunity to see a total eclipse
in Australia is from remote Exmouth, W.A. in 2023. In July 2028,
a total eclipse will cross the whole continent starting in the
Kimberley crossing many regional towns and centers and finally
being visible across Sydney.
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The eclipse date and
time
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The eclipse path
The first point of contact of the Moon's shadow with the Earth's
surface occurs north east of the Kakadu National Park, in a line
extending northeast of Ubirr Rock. The shadow travels east across
Arnhem Land, crosses into the Gulf of Carpentaria coast at the
north end of Blue Mud Bay. It strikes land again on Cape York
Peninsula near Wallaby Island. The centerline crosses the Eastern
coast 30km north of Cairns about halfway between Cairns and Port
Douglas. After that it crosses Green Island before heading south
east across the Pacific where it doesn't touch land again.
The 2012 total eclipse can be seen along the coast from a 140 km wide path. The path crosses the coast at an angle so that the 140km wide path covers a 200km swathe of coastline between Innisfail in the south to Cedar Bay National Park about half way between Cape Tribulation and Cooktown. Outside this area, a partial eclipse only will be visible. Just outside the total path, for example south Innisfail, a 99.9% partial eclipse is visible. Be in no doubt, a 99.9% partial eclipse is not almost the same as the spectacle of a total eclipse. If you live near the edge of the path, get in the car and drive into the path of totality. Anywhere between Gordonvale and Port Douglas on or near the coast are the best places to see the eclipse. The duration is longest in this area. The total part of the eclipse lasts for two spectacular minutes anywhere between Cairns and Port Douglas. To the north and south, duration gets progressively shorter and shorter until, near the southern and northern limits, it only lasts for a few seconds. For folks living in or near Innisfail, watch from at least 20km north of Innisfail say Babinda or Bramston Beach to get a decent duration of about 1m 20s.
This map is a low-resolution illustration and only intended to show the relative positions of places mentioned in the text. High resolution maps and predictions of all eclipse paths are available from the web site links provided at the end of this document.
Location, Location
Location
Any place with
a good view of the east horizon will make a great place to watch
the eclipse. Though the beach immediately comes to mind, the
tide will probably be coming in as the eclipse progresses. Some
beaches may become covered by tides . New Moon occurs at 06:38.
A high tide usually occurs mid-morning (9-10am) on the day of
a new Moon in this region. Tide height will be between 2.5-3.2m.
So the tide will be low at 3am about the time you select your
observing location. High tide will be coming in during the eclipse
and high tide will occur about two hours after the total eclipse
ends
Some beaches north of Cairns do not get covered at high tide. These include Kewarra beach, Trinity beach and Palm Cove. If you are just looking by eye or using a camera and tripod, these beaches are ideal. Expert observers who bring telescopes should probably retreat inland a few kilometres to shelter from any onshore winds. The many open fields between Skyrail and the airport should provide adequate cover. These agricultural fields though unfenced, are private property. Please treat any crop plantings with due respect. Use the verges, don't trample the tilled fields and don't drive onto ploughed soil. You might damage the plantings or become deeply bogged.
Example of
an open field suitable for anyone wanting to get away from the
coast. 
Charter boats will be offering cruises to take people out to watch the eclipse at sunrise from the boat or on diving platforms on ocean reefs followed by reef viewing, diving or snorkeling after. These reef and sky tours present a unique way to experience the eclipse. Be aware that the reef platforms are pontoon platforms that will move with the ocean swell. The boats are too small to be fitted with stabilizers. If you are using any sort of telescope, binoculars or camera and tripod, you should probably stay on solid ground. You don't need to use binoculars or telescopes to enjoy an eclipse. So much is going on around the whole sky many choose to just look with the naked eye. If you just want to look and enjoy, these reef and sky charters might be just the ticket.
Eye Safety
A few minutes
after sunrise, the eclipse begins. The Sun first goes through
a partial eclipse that lasts for about an hour before the total
eclipse begins. During this time, there is great danger of eye
damage if you don't protect your eyes. The whole eclipse lasts
for about two hours.
The total part of the eclipse lasts for about 2mins in the middle of the two hours. During this time, the photosphere, the bright surface of the Sun, is completely covered by the Moon so totality can be safely observed without using eye protection. The total eclipse is only as bright as a full Moon and regardless of what you might read, there are no dangerous rays that will damage your eyes during this period. The two phenomena known as diamond rings mark the start and end of the safe period and it's only during the between the two diamond rings that it is safe to look without eye protection.
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The Sun goes through an hour of partial eclipse before and an hour after the total eclipse. During both periods, there is great danger of eye damage occurring.
How to protect your eyes during the partial eclipses?
During the partial eclipses both before and after totality, you must use special techniques to protect your eyes. Looking at the Sun at anytime during an eclipse or even on a normal day can burn the retina causing permanent eye damage. The Sun is no more dangerous during a partial eclipse than it is on any other day. On a normal day, if you glance at the Sun or get the Sun in your eyes for example while you are driving, you don't go blind. But you don't stare at the Sun. During the eclipse, you don't have to protect your eyes from glancing contact with the Sun any more than you do on a normal day. The problem is that during the eclipse, there is a temptation to stare at the eclipse for extended periods especially as the Sun gets covered. Staring can cause burns on the retina leading to permanent blind spots.
Using found materials from around the home as defacto solar filters is very dangerous. These materials don't filter the dangerous UV and IR rays and can lead to blind spots even though the image looks dark enough to the eye. Examples of unsuitable filters include pinholes, photographic film negatives, cd's/DVD's, smoked glass and silvered confectionery wrappers among many others. There are no materials found around the home that will safely filter the Sun's high intensity light. Some of these materials might look similar to solar filters but they are definitely not safe. The best policy is to assume that if it hasn't been made for the purpose, it isn't safe.
Even during the final minute when the Sun is almost completely covered and the ambient lighting begins to looks like like twilight, the energy in the very thin crescent is more than capable of causing a permanent burn to the retina.
There are two accepted safe methods for watching a partial eclipse. One is to look through some sort of specially made filter material, the other is to use some sort of projection method.
Filters
Eclipse shades are special cardboard frame sunglasses or hand held
rectangular cardboard viewers with properly made solar filters
built-in. These should be available for purchase at many tourist and
retail outlets around Cairns. Check that the glasses have the European
Community Certification (CE) as this is the safety standard that is
being adopted by the QLD government. Eclipses occurred so infrequently
in Australia over the past 100 years that no Australian Standard
exists. The Starfield 7 glasses in the accompanying advertisement are
CE certified and can be purchased and used with confidence and possibly
at less cost than he street price in Cairns. These glasses are
the most convenient filtration
method. Do read the instructions. Some of these shades are not rated
for continuous viewing but for viewing 30 seconds at a time. A pair of
eclipse shades will probably cost less than $10.00 . These cardboard
glasses use special filter materials that effectively cut all
wavelengths of light including the dangerous IR and UV that defacto
materials pass to your eyes. Your eyesight is definitely worth the
investment. Other suitable filters are a number 14 arc welding filter
available from welding suppliers or a special solar filters available
from astronomical suppliers designed to be attached to telescopes or
binoculars.
Girl
in a bus, Jinta, Gansu Province, China testing Visit Starfield 7's Ebay store or send an enquiry email
her eclipse shades before
the 2008 eclipse began
to starfield7@gmail.com
If you can't get filtered eclipse glasses, the oldest safe method is the projection method. Cut the side out of a large cardboard box. Punch a 5mm hole in the side.
The Sun will be rising in the east. Stand about 3-5m away from the east wall of a white walled building. With your back to the Sun hold the card up so that its shadow falls on the wall. In the middle you will see a small image of the partially eclipsed Sun.
What will you see?
The Sun will rise at 5:34am. About ten minutes later the partial
eclipse will begin. If you are on the Cairns waterfront, the
Sun will remain hidden behind Cape Grafton for 15-20minutes.
It will rise over the cape about one third eclipsed. The partial
eclipse will take 54 minutes. As totality approaches, the solar
crescent will become very thin. Though thin, it is still too
dangerous to look at without any eye protection.
About a minute or two before the start of the total eclipse, look to the west. You will see the Moon's shadow moving across the sky from west to east. West to east may at first seem a little odd. Even though the Moon rises in the east and sets west due to the Earth's rotation, the Moon actually orbits the Earth from west to east. So the shadow being cast by the Moon also travels from west to east. The shadow will move slowly when it is near the western horizon, very quickly as it passes overhead and to the east. When this shadow reaches the Sun in the east the total eclipse begins.
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During the minute or so before the eclipse the lunar shadow covers the sky. The ambient light will dim dramatically reducing by a factor of about a thousand. If you have a really accurate time source, you can remove your eclipse glasses about ten seconds before the start of the total eclipse. The Moon's shadow by now will have moved right across to cover the whole of the sky. When the front edge of the shadow reaches the Sun, the diamond ring will form and the total eclipse begins. The diamond ring is a bright ring of light surrounding the dark lunar disk with one dazzling bright white point of light.
The diamond ring light is the last little bit of the Sun's surface visible through the deepest valley that points at Earth on the the edge of the Moon. Even when this disappears, it won't go completely dark, more like a very deep twilight. Your eyes will quickly adjust to the new low light level. As your eyes adjust, the Sun's corona will become visible. The corona is composed of very hot electrically charged gas - a plasma. The coronal gas has a temperature of about a million degrees and it stretches millions of kilometres out into space. The charged particles are distributed along and reveal the Sun's magnetic field lines similar to the way your science teacher at school might have used iron filings to reveal the field of a magnet.
The corona will appear to grow. This is just an illusion. The outer corona is fainter than the inner corona. As your eyes adapt to the dark, they become more sensitive so you are able to see fainter parts of the outer corona so it seems to grow. Nonetheless, the effect is mesmerizing.
As totality ends, a diamond ring dazzles you as it seems to explode from the opposite side of the Moon to the first diamond ring. This one seems much brighter than the first because your eyes are adapted to the dark. The appearance of the second diamond ring is your signal to put your eye protection back to work. Put on your eclipse shades or use your projector and don't look directly at the Sun for the remainder of the eclipse. The Moon spends another hour in partial eclipse as it gradually uncovers the Sun before the event is all over.
