Eclipses in 2017

There are four eclipses in 2017, two each of the Sun and moon. Four is the minimum number of eclipses there can be in a year.

The first solar eclipse on February 26 is annular with a path starting at sunrise in the south Pacific Ocean well west of Southern Chile. Its path takes it over Southern Chile and Argentina before heading off across the Atlantic Ocean towards Africa. It make landfall again in southern Angola near the time of sunset. The eclipse ends at sunset in the southern-most part of the Congo Republic near its border with Zambia. The second solar eclipse is total, it starts at sunrise in the northern Pacific and crosses the continental U.S.A. from Oregon to South Carolina. The eclipse ends at sunset in the Atlantic west of Africa. No part of either solar eclipse is visible from New Zealand.

By contrast to the solar eclipses, the two lunar eclipses are very paltry affairs. Neither are total; the first on February 11 is penumbral, the second on August 7 is partial. The lunar eclipse on February 11 takes place 2 weeks before the annular eclipse of the Sun. It is entirely a penumbral event, with the Earth only obscuring part of the solar disk as seen from the moon. 98.9% of the moon’s diameter will be in the penumbra while a sliver, 1.1% of the diameter wide, near the moon’s south pole, will remain in full sunlight. No part of the moon’s disk will enter the Earth’s full shadow. The entire eclipse will be best seen from Africa, Europe and the Atlantic Ocean. At the second lunar eclipse on August 7 the moon will move a little more deeply into the Earth's shadow so that at its maximum almost one-quarter of the moon’s diameter will be completely shaded from the Sun. The remaining 75% will be in the part shadow, the penumbra. In this case the southern quarter of the moon will be darkened. The remainder, still partly sunlit, will be somewhat dimmed. The start of the eclipse will be visible from New Zealand, with the moon setting after mid eclipse. Australia sees the whole of the eclipse.

More information on eclipses can be obtained at the NASA eclipse pages: http://eclipse.gsfc.nasa.gov/.

Diagrams, maps and the tables showing times of phases of lunar eclipses have been prepared using David Herald's Occult 4 program.

Viewing Eclipses of the Sun and Transits of Planets across the Sun

Whenever the Sun is to be observed safe viewing methods must be used. Any attempt to view the Sun directly could result in instant blindness.

The safest way is to project the image of the Sun onto a suitable screen. Alternatively a suitable, specially designed, Solar filter may be placed in front of the telescope.

It is not safe to use a filter at the eyepiece as the focussed heat from the Sun could shatter it. If unsure of safe methods consult your local astronomical society about suitable ways of observing Solar events.

Penumbral eclipse of the Moon 2017 February 11

At this eclipse of the moon a maximum of 98.9% of the moon’s diameter moves into the Earth’s penumbral shadow, with 1.1% remaining in full sunlight. The uneclipsed sliver will be near the moon's south pole, while the most northerly parts of the moon will be close to, but not in, the umbra. So we may expect this part of the moon to be distinctly dulled, with the surface brightening further south.

In a penumbral eclipse an observer on the moon would see part of the Sun covered by the dark Earth. In this eclipse the greatest amount covered would be seen in the north. As the observer moved south on the moon less of the Sun would be covered until in the far south no part of the very low Sun would be hidden.

As seen from the Earth the moon will be visible from northeast Canada and eastern South America, Europe. Africa and the Middle East throughout the eclipse. Changes in the moon's brightness will not be very marked. In the remainder of north and south America the moon will rise during the eclipse. As seen from much of eastern Asia, the moon will set during the eclipse, as it will from most of Indonesia. No part of the eclipse is visible from Australia, New Zealand or the western parts of the Pacific, including Japan and the Philippines.

Times of the start, maximum and end of the eclipse are shown on the diagram, which also shows the parts of the Earth from which the various stages are visible. The coloured circles at the top left shows the path of the moon (outlined and numbered 1, 4 and 7) through the penumbral part of the Earth’s shadow.

Annular eclipse of the Sun, 2017 February 26

The annular eclipse of the Sun on February 26 starts in the southern Pacific Ocean well west of Southern Chile. The Sun will rise in annular eclipse at a point about 3500 km west of the southern coast of Chile and about 1000 km south of Easter Island (I. de Pasaua). As it rises, 97.7% of the diameter of the solar disk will be covered by the moon. The width of the annular path will be 96 km and the duration of the annular eclipse 82.4 seconds.

At first the annular path will move slightly south of due east to cross the coast of Southern Chile about 18 minutes later at the I. Rivero. Inland in Chile it passes close to Coihaique and then Facundo in Argentina. By then the Sun will be 98.6% covered and the annular phase will last 64.5 seconds. The annular path leaves the east coast of Argentina close to Cape Dos Bahias some 11 minutes after it crossed the west coast.

As the path moves out across the Atlantic Ocean it swings more to the northeast. Maximum eclipse occurs well out in the Atlantic Ocean at about longitude 31° W and latitude 35° south at near local midday. At the maximum 99.2% of the solar disk will be covered by the moon, and the annular phase will last only 44 seconds. The increase of the amount of Sun covered and the consequent shortening of the annular phase are due to the Earth’s surface being closer moon when the latter is highest.

After eclipse maximum the path of the eclipse continues across the Atlantic passing well south of St Helena. It crosses the coast of Africa in southern Angola a little to the north of Mocamedes. By then the Sun will be near setting, a little way inland it will indeed set before the end of the eclipse although the annular phase will remain visible as it crosses Angola and enters the extreme south of the Congo Republic along the border with Zambia. The annular eclipse ends as the sun sets to the northwest of Lubumbashi about 3 hours 15 minutes after it started in the Pacific. At its end 97.8% of the solar disk will be covered, with the annular phase lasting 77.4 seconds.

No part of the eclipse is visible from Australia nor from New Zealand.

Partial eclipse of the Moon 2017 August 7

At this eclipse a maximum of just under 25% of the moon's diameter will be immersed in the umbral, full shadow of the Earth. In this case it will be the southern part of the moon which is darkened. The remainder of the moon will be in the penumbra, partial shadow, of the Earth. The entire eclipse is visible from the east coast of Africa central Asia except the north Indonesia and Australia except the eastern seaboard. The moon rises during the eclipse as seen from the rest of Africa, Europe and western Asia. Further east the moon will set during the eclipse as seen from much of the remainder of Asia, Indonesia and Australia. From the New Zealand the eclipse will start with the moon low to the west. All parts will see the beginning of the umbral phase, visible in its entirety from the South Island, before the moon sets.

Total eclipse of the Sun 2017 August 21

The total eclipse on August 21 starts at sunrise in the north Pacific Ocean about half way between Hawaii and the eastern most part of Siberia. The total eclipse moves eastwards to enter the U.S.A. in Oregon a little south of Portland with Salem in the path. After crossing the U.S.A. the eclipse leaves the country from South Carolina with Charleston in the path. It heads across the Atlantic Ocean towards Africa, but ends at sunset still west of the continent and to the south of the Cape Verdi Islands.

The greatest duration of totality is just over 160 seconds and occurs along a belt from south of St Louis, Missouri, to north of Nashville in Tennessee. The maximum path width of totality is 155 km.

No part of the eclipse is visible from New Zealand or Australia apart from the western coast of the latter where the eclipse starts as the Sun sets.

For a detailed map showing the path across the U.S.A. Eclipse path

Total eclipse of the Sun 2017 August 21