Eclipse Resources

A Total Solar Eclipse (total eclipse of the Sun) will occur over Northern Australia early in the morning of 14 November 2012. This rare and spectacular phenomenon is probably the most awe inspiring event in the natural world. At the same time the whole of Australia will experience a Partial Solar Eclipse.

WARNING: Never look directly at the bright surface of the Sun without suitable eye protection or permanent eye damage may result. This applies at any time and especially during the partial phases of a solar eclipse. Refer to the safe viewing advice towards the bottom of this page.

What is a Total Solar Eclipse?

The Sun and Moon appear in the sky to be roughly the same size but their sizes are actually very different. By a fortuitous coincidence the Sun is about 400 times larger than the Moon but the Sun is also about 400 times further away. So the Moon is able to just cover the Sun completely during a total solar eclipse.

An eclipse of the Sun occurs when the Moon, in its orbit around the Earth, passes between the Earth and the Sun and casts a shadow on the Earth. This can only happen at new moon. There are two parts to the Moon’s shadow. The dark cone shaped part of the shadow is called the umbra. From any location within the umbra, the Sun will be completely obscured (“eclipsed”), its bright light will be cut off, the sky will go dark and a total solar eclipse will occur. The lighter part of the shadow is called the penumbra. From locations within the penumbra the Sun is only partially hidden and from these locations there will be a partial solar eclipse, as the Sun will only be partly obscured. The period during which an eclipse is total is called totality.

Fig 2-1wAs the Moon orbits the Earth and the Earth rotates, the Moon’s shadow moves across the Earth’s surface from west to east, with the umbra tracing out a narrow path called the path of totality. For any location in the path of the totality, the Moon will firstly appear to gradually cover the Sun in the partial phase of the eclipse. As the umbra arrives at that location, the Sun will be completely covered and there will be a total solar eclipse. As the umbra moves on, the Moon from that location will appear to gradually uncover the Sun in the final partial phase of the eclipse.

The 14 November 2012 Eclipse Path of Totality

The path of totality for the eclipse of 14 November 2012 is shown in the diagrams below. The path starts at sunrise in the Northern Territory east of Darwin and then travels across the Gulf of Carpentaria and across Cape York. Here the path is about 140km wide and the Moon’s shadow will be traveling at about 15,000 kilometres per hour. It crosses the east coast of Cape York in the Cairns and Port Douglas region. The umbra then passes out over the South Pacific Ocean traveling to the north of New Zealand, making no further landfall until it ends at sunset just short of South America.

TSE 2012 Track 2TSE track

The Partial Eclipse

At any point on the Earth’s surface outside the path of totality but crossed by the penumbra, the Moon will only partly cover the Sun, reaching a point of maximum coverage and then uncover the Sun. So this point will have only a partial solar eclipse.  A partial solar eclipse will be experienced over the whole of Australia.

The map at above right shows the path of totality across north Queensland and also shows how the partial eclipse will appear at maximum coverage of the Sun at locations outside the path of totality. The magnitude of the eclipse (maximum coverage of the Sun’s diameter) depends mainly on the distance of the location from the path of totality.

The table below lists the times of the partial eclipse, the eclipse magnitude and elevation of the Sun at locations across Queensland.

Location

Start

Partial

h:m am

Time of

max eclipse

h:m (am)

Magnitude

(max cover of

Sun’s diameter)

End

Partial

h:m (am)

Sun

Elevation

(at max)

Brisbane

5:56

6:54

83%

7:59

26º

Bundaberg

5:53

6:51

89%

7:55

24º

Charleville

5:56

6:51

78%

7:51

19º

Charters Towers

5:48

6:43

94%

7:44

16º

Cooktown

5:44

6:38

99%

7:38

13º

Coolangatta

5:57

6:56

82%

8:00

27º

Dalby

5:56

6:53

82%

7:57

24º

Gladstone

5:51

6:49

90%

7:53

23º

Gympie

5:55

6:52

86%

7:57

25º

Ipswich

5:57

6:54

83%

7:59

26º

Longreach

5:52

6:47

83%

7:46

16º

Mackay

5:48

6:45

94%

7:48

19º

Maryborough

5:54

6:52

88%

7:56

25º

Mount Isa

  5:51*

6:43

85%

7:41

10º

Noosa

5:55

6:53

86%

7:58

26º

Rockhampton

5:51

6:48

90%

7:52

22º

Roma

5:56

6:52

81%

7:53

22º

Toowoomba

5:57

6:54

82%

7:58

25º

Townsville

5:47

6:42

96%

7:44

16º

Tully

5:46

6:41

99%

7:42

15º

Weipa

  5:42*

6:35

95%

7:34

  8º

                                           (* = before sunrise)

During a partial solar eclipse the light level will drop to an extent dependent on the magnitude of the eclipse. Because our eyes are very good at compensating for varying light levels, this will often go unnoticed unless the Sun is reduced to a very thin crescent.

During these partial phases, images of the crescent shape of the Sun can be seen projected under trees on the ground or onto adjacent walls, as the gaps between leaves act as pinhole projectors. Interesting crescent shapes can be seen using items with one or more holes in them such as a kitchen colander or a loosely woven straw hat. Shadows become unnatural as the crescent Sun becomes thin, being very sharp in one direction and blurry at right angles. This is easy to see by observing the shadow of both hands with the fingers on one hand orientated at right angles to the fingers on the other hand.

Never look directly at a partial solar eclipse without suitable eye protection or permanent eye damage may result. Refer to the safe viewing advice towards the botton of this page.

The Total Solar Eclipse

From within the path of totality, the eclipse begins with partial phases as the Moon gradually covers the Sun over a period of about an hour. As totality approaches, the Sun is reduced to a thin crescent, the light begins to fade and an ominous darkening of the sky (the Moon’s shadow) approaches silently from the west. The temperature can drop significantly. In the final minute or so the sky darkens dramatically, just like switching from day to night. In the final few seconds before totality, the last brilliant parts of the Sun’s surface shine through valleys around the edge of the Moon in a shimmering display called Baily’s beads. Finally the beads are reduced to a single point and the Sun looks like a dazzling diamond ring. As the last bright point winks out, the Sun’s pink upper surface called the chromosphere can be seen in an arc around the edge of the Moon and usually prominences which are small pink loops of plasma extending above the chromosphere, are visible. The onrushing darkness arrives and envelops observers and the whole sky becomes dark in a surreal twilight. The Moon appears as a black disk in the sky surrounded by the pearly white corona, the Sun’s outer atmosphere composed of ionised gas. The corona curves out from the Sun, usually in a pattern formed by the Sun’s magnetic field. Bright stars and planets can be seen. There is a glowing light around the horizon which has a sunset colour caused by the scattering of different wavelengths of light in the atmosphere

TSE Diamond

TSE Sky 2TSE Corona

At the end of totality the sequence is reversed, with prominences, chromosphere, diamond ring and Baily’s beads again being visible. The Moon then gradually uncovers the Sun, taking about an hour until the final partial phase is over.

TSE 2012 TrackIt is the dramatic change from daylight to night, the ominous black darkening approaching from the west, the chill in the air and the disappearance of the Sun in an otherwise normal day that so terrorised ancient peoples. Even today, when we understand what is happening it is still a spine tingling and awe inspiring event.

The map to the right shows the path of totality on the east coast of Cape York and the approximate duration of totality over the width of the path. At the time of the total eclipse, the Sun will be a little south of due east and about 13 degrees above the horizon on the east coast and about 9 degrees above the horizon on the west coast. A good view low down to the east will be essential to see the eclipse. It is a good idea to check the position of the Sun in the days before the eclipse at the same time as the eclipse from your location. A low horizon will also help in being able to see the approaching Moon’s shadow and the all round sunset colours. As long as the weather is clear on eclipse morning, any of the beaches from Cairns north to Wonga Beach (a few kilometers north of Port Douglas) should provide a view of the eclipse. If there is cloud along the coast a location further inland may be clearer.

To observe the total solar eclipse you must be in the path of totality. The total eclipse will be seen from the major centres of Cairns, Atherton, Mareeba, Mossman Port Douglas and the northern part of Innisfail. The exact time of the start of the total eclipse will depend on the location. Locations closer to the centerline of the shadow path will have a longer eclipse. The total eclipse duration will also increase towards the east coast. The maximum duration on the Australian mainland is about 2 minutes and 4 seconds near the point where the centre of the path crosses the east coast near Oak Beach just south of Port Douglas.

If you live outside the path of totality, it will certainly be worth travelling to see the eclipse. From locations outside the path of totality, even if just outside, only a partial eclipse will be visible. Because the change in light level between normal Sun and a total eclipse is about a million to one, even if the Sun is covered 99% the sky will still be about 10,000 times brighter than the total eclipse and none of the dramatic effects of totality can be seen. The towns of Dimbulah and Malanda and the southern part of Innisfail are outside the path of totality.

The table below lists the timing details for various locations.

Location

Start

Partial

h:m (am)

 1st contact

Start

Totality

h:m:s (am)

 2nd contact

Duration

of

Totality

min:secs

End

Partial

h:m (am)

 4th contact

Sun

Elevation

(at total)

Atherton

5:45

6:39:43

     29s

7:41

14º

Babinda

5:45

6:39:23

1m 19s

7:41

14º

Cairns CBD

5:45

6:38:36

1m 58s

7:40

14º

Daintree

5:44

6:37:53

1m 55s

7:39

13º

Gordonvale

5:45

6:38:52

1m 47s

7:41

14º

Innisfail CBD

5:45

6:40:10

     19s

7:41

15º

Kuranda

5:45

6:38:28

1m 59s

7:40

14º

Kowanyama

  5:45*

6:37:08

1m 35s

7:37

10º

Lakeland

5:44

6:37:40

1m 30s

7:39

13º

Laura

  5:44*

6:37:33

     57s

7:38

12º

Mareeba

5:45

6:38:45

1m 41s

7:40

14º

Mossman

5:44

6:38:01

2m 03s

7:40

13º

Mount Molloy

5:45

6:38:17

1m 59s

7:40

14º

Palm Cove

5:45

6:38:21

2m 02s

7:40

14º

Pormpuraaw

  5:44*

6:36:26

1m 54s

7:36

  9º

Port Douglas

5:44

6:38:03

2m 03s

7:40

14º

Wujal Wujal

5:44

6:37:55

1m 07s

7:39

13º

Yarrabah

5:45

6:38:34

2m 00s

7:40

14º

                                      (* = before sunrise)

Never look directly at the partial phases of a total solar eclipse without suitable eye protection or permanent eye damage may result. Refer to the safe viewing advice towards the botton of this page.

TSE 2012 Stars 3Stars and planets during the eclipse

During the total part of the eclipse the sky becomes so dark that some planets and the brightest stars usually become visible. At the time of the eclipse, the planets Venus and Saturn will be higher in the sky than the Sun, while Mercury will be between the Sun and the horizon. These planets and the Sun with the Moon will form a line. This is because all the planets are in approximately the same plane as they orbit the Sun. During a total solar eclipse is the only time that this can be seen in this way. It may be possible to see the bright stars Sirius and Canopus as well as the stars of the Southern Cross.

How to View the Eclipse Safely

Never look directly at the bright surface of the Sun without suitable eye protection or permanent eye damage may result. It is never safe to look directly at a partial solar eclipse or the partial phases of a total solar eclipse without the proper equipment and techniques. Even when 99% of the Sun’s surface (the photosphere) is obscured during the partial phases of a solar eclipse, the remaining crescent Sun is still intense enough to cause a retinal burn, even though illumination levels may be comparable to twilight. Failure to use proper observing methods may result in permanent eye damage and severe visual loss.

Safe viewing techniques must be used for the partial eclipse that will occur across Queensland and for the partial phases that precede and follow the total eclipse.

The Queensland Government has issued the following advice on how to safely view the eclipse.

1.     Never look directly at the Sun without proper eye protection. It is possible to suffer serious and permanent eye damage by looking at a solar eclipse the wrong way, even for a very short time.

2.     Always use solar eclipse glasses, or filters that have been made specifically to attach to hand-held glasses, telescopes or binoculars for safe solar eclipse viewing.

3.     Look for filters that have been appropriately certified against the European Standard for personal eye equipment (EN 1836:2005+A1:2007) or the Australian Standard for welding shields and goggles with a lens category higher than 12 (AS/NZS 1338.2:1992 & AS/NZS 1338.1:1992).

4.     Before using solar eclipse glasses or filters, check to see if they are scratched or damaged. If so, do not use them as they will not fully protect your eyes.

5.     Do not use solar eclipse glasses or filters that do not show compliance with the Standards listed above – they may do you more harm than good.

6.     Do not look directly through binoculars, telescopes or camera optical viewfinders. It is not safe to use regular sunglasses, exposed film or x-ray film to view a solar eclipse.

7.     Alternative safe viewing methods include using pinhole, binocular or telescope projection. Visit http://sunearthday.nasa.gov/2012/transit/viewing.php for details on how to do this safely. For information on filters for telescopes or binoculars visit http://eclipse.gsfc.nasa.gov/SEhelp/safety2.html.

This advice is available on the following Queensland government website: http://www.fairtrading.qld.gov.au/safe-viewing-of-astronomical-events.htm.

A pinhole projector can be made using two pieces of card, one with a small hole in it.  Stand with your back to the Sun and project an image of the Sun through the hole in the card onto the other card.  Do NOT look at the Sun through the hole in the card.

Pinhole proj 2Images of the eclipsed Sun can also be seen under trees with the gaps in the leaves acting as pinholes. A loosely woven straw hat also works well.

Eclipse Glasses

The NASA solar eclipse website also has information describing how to view a solar eclipse safely. They advise that “the total phase of an eclipse can and should be viewed without any filters whatsoever. The naked eye view of totality is not only completely safe, it is truly and overwhelmingly awe-inspiring!” See http://eclipse.gsfc.nasa.gov/SEhelp/safety2.html for the full text.

So, if you are in the path of totality (and you must be certain of this) you must remove your filter (eg eclipse glasses) in order to see the total part of the eclipse, but you must keep the filter on until the Sun is no longer visible (even the tiniest part) and it goes very dark; and you must look away or replace the filter immediately any part of the Sun reappears.