On November 13, 2012 (UT), one of the great natural events takes place when a total solar eclipse is visible from the southern hemisphere. This time, the narrow band of totality streaks mainly across the southern Pacific Ocean, but for a short time, just after sunrise it does touch land in northern Australia.
A solar eclipse occurs when the Moon passes between the Earth and the Sun, thereby totally or partially obscuring the Suns image for an observer on Earth. Total eclipses are only possible due to a piece of natures luck. By sheer coincidence the Sun is about 400 times larger in size than the Moon but also about 400 times more distance. Hence, to the observer on the ground both the Sun and the Moon present about the same (apparent) size in the sky. The apparent size or diameter of the Sun and the Moon do exhibit small variations; at times the Moon appears slightly larger in the sky than the Sun and vice-versa.
A total solar eclipse occurs when the Moon's apparent diameter is larger than the Sun, blocking all direct sunlight and turning day into darkness. This path of totality occurs inside a narrow band that touches the surface of the Earth. It has a maximum width of only 267 kilometres (167 miles). On the other hand, for a partial solar eclipse the shadow is many thousands of kilometres wide and the partial eclipse is visible over a much larger region.
Eclipse Path on November 13, 2012
The diagram below shows the visibility of this total eclipse. The path of totality (Moons umbral shadow) crosses the South Pacific Ocean and apart for a small part of northern Australia it does not make landfall. The penumbral shadow of the Moon (partial part of the eclipse) is visible from regions covering the South Pacific (including Australia and New Zealand), southern South America and Antarctica.
Totality in Australia begins at Garig Gunak Barlu National Park (250 kilometres east of Darwin) on the northern coast of the Northern Territory at 6:05am local time on December 14 (20:35 UT on December 13). The fast moving shadow then heads out to the southeast, crosses quickly over the Gulf of Carpentaria before reaching the Cape York Peninsula only two minutes later.
Next in line for totality is Cairns, which happens to be the only populous city inside the path of umbral shadow. For the 150,000 residents, they will experience an early morning total eclipse on November 14 lasting exactly 2 minutes with the Sun only 14 degrees above the eastern horizon. Totality starts at 6:38:33am local time (20:38:33 UT time). Cairns city centre is positioned about 30 kilometres south of the central line of totality resulting in about 5 seconds less totality than for those positioned exactly along the line. From Cairns, the partial phase of eclipse starts at 5:45am and finishes at 7:40am.
Once the umbral shadow has left Australia the track moves back over the ocean. At 22:11:48 UT, the point of greatest eclipse occurs in the South Pacific Ocean, approximately 2000 km east of New Zealand. Totality at greatest eclipse lasts for 4 minutes and 2 seconds with the width of the path 179 kilometres.
The shadow then continues across the vast Pacific Ocean until the umbral shadow's path ends about 800 kilometres west of Chile at 23:48 UT.
For other areas, parts of northern New Zealand including Auckland will experience a partial eclipse with over 80% of the sun obscured. Christchurch and points north will see at least 60% of the Sun obscured. Parts of central Chile, specifically the Los Ríos and Los Lagos regions from Valdivia (63% obscured) south to Quellón (54% obscured) will see a partial eclipse with over half the Sun obscured at sunset. Points north up to about Santiago will see the eclipse begin as the sun is setting.