A total solar eclipse touches Australia

Lucky observers can stand in the Moon’s shadow during daylight November 13/14.
By | Published: September 27, 2012
The Sun’s corona shows up only during the few brief moments of totality. The appearance of our star’s million-degree outer atmosphere changes from one eclipse to another. On August 1, 2008, delicate streamers and broad brushstrokes filled the space surrounding the Moon’s black disk. // Credit: Anthony Ayiomamitis
The most spectacular event of 2012 occurs November 13/14 as the Sun, the Moon, and Earth line up once again to create a total solar eclipse. Unlike the annular eclipse nearly six months earlier, however, which hit two continents and several large cities, totality touches only one continent and a few modest towns.

Remote observing note: Join Astronomy Contributing Editor Bob Berman in Cairns, Australia, as he broadcasts the total solar eclipse live with SLOOH Space Camera at http://events.slooh.com.

The place to be the morning of the 14th is northern Australia. The path of totality begins along the coast of the Northern Territory, about 155 miles (250 kilometers) east of Darwin. The track then crosses the Gulf of Carpentaria before cutting across the Cape York Peninsula in northern Queensland. After that, the path heads across the Pacific Ocean and doesn’t make landfall again.

For those who want to maximize both the length of totality and the chances for favorable weather, the best bet is to view from Queensland’s east coast or a bit offshore. From Cairns, famous as the gateway to the Great Barrier Reef, the Sun rises at 5:35 a.m. local time, and the partial eclipse begins 10 minutes later. Totality starts at 6:39 a.m. and lasts precisely two minutes. Viewers on the shadow’s centerline some 19 miles (30km) north of Cairns gain an extra five seconds of totality. Climate statistics suggest the odds of sunshine in the early morning hours along the Australian coast are around 65 percent, and a few percentage points better in the offshore waters.

“Viewing a total solar eclipse is unlike any other sight,” says Astronomy magazine Contributing Editor Mike Reynolds. “It’s the most dramatic event most people will ever see.”

A few minutes before totality, as the slightly larger Moon advances on the dwindling Sun, the solar crescent starts to break up. Mountains on the Moon’s limb poke through the tiny sliver while sunlight continues to stream through lunar valleys. At that time, viewers see a phenomenon astronomers call Baily’s beads.

The path of totality makes landfall only in northern Australia, in Queensland and the sparsely populated Northern Territory. Most eclipse chasers will opt for sites along the coast near Cairns. Astronomy: Roen Kelly
Then, a few seconds before the Sun disappears, the jewel-like beads shrink to a brilliant solitaire known as the diamond ring. This is the final moment of glory for the eclipse’s partial phases. Once the ring disappears, it is safe to look at the eclipsed Sun for the duration of totality without any solar filters.

The most spectacular aspect of the total phase is the Sun’s corona, a pearly white light that typically stretches two or three times our star’s diameter. Look for delicate loops, swirls, and streamers throughout the corona; use binoculars or a low-power telescope to see more detail.

“Don’t forget to take a few seconds to look around the sky for bright planets and stars,” Reynolds suggests. “But not too long. The main show is the Sun, and two minutes zooms by pretty fast!”

Solar prominences — the fiery red tongues of gas that arc above the Sun — may also appear around the Moon’s edge. Like the corona, prominences appear only during total solar eclipses when the Moon hides the Sun’s brilliant surface from view.

Barely two minutes after totality begins, a second diamond ring announces its conclusion. Viewers then must replace their solar filters or put on their eclipse glasses to safely enjoy the partial phases as they play out in reverse.

Learn more about this year’s total solar eclipse in the December issue of Astronomy, on newsstands November 6.