Eclipses in 2018

There are five eclipses in 2018, three partial eclipses of the Sun and two total eclipses of the moon. In 2018 it is the Lunar eclipses that are visually interesting, in contrast to 2016 and 2017. On the other hand the Solar eclipses are partial, with only a small fraction of the Sun’s disk obscured, so presenting little to see. Also the areas from which they are visible are largely the polar regions although the final eclipse of the year is visible from much of China.

Viewing Eclipses of the Sun. Caution needed.

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.

Total Eclipse of the Moon 2018 January 31/February 1

In contrast to the partial Solar eclipses, both the Lunar eclipses for 2018 are total. The first is on the night of January 31/ February 1. It is entirely visible from New Zealand and most of Australia. With the maximum eclipse at 2.30 am New Zealand is excellently placed for viewing, although, since it is during the summer, the moon will not be very high. The total eclipse lasts for just over 75 minutes with some part of the moon being in full shadow for over three hours.

The moon starts to enter the penumbra of the Earth’s shadow just before midnight NZDT (10:50:50 UTC) January 31. There will be little change in the moon’s appearance until it starts to enter the umbra about an hour later, by then February 1 for NZ. By that time the moon will have risen for all of Australia. The total eclipse with the entire moon in the Earth’s shadow, will start another hour later. Mid eclipse is at 2.30 am NZDT, (13:29:51 UTC).

Apart from New Zealand and Australia, the total eclipse is also visible from eastern Siberia, Japan, China and other southeast Asian countries, Indonesia and most Pacific Islands. The start of the eclipse is visible from most of North America but the moon sets before the end of totality for much of the continent, the exception being Alaska and the western seaboard.

The diagrams show the hemisphere of the Earth from which each stage of the eclipse is visible.

Total Eclipse of the Moon 2018 July 27/28

This eclipse is particularly favourable for countries bordering the Indian Ocean. New Zealand sees its start as the moon moves into the penumbra and begins to enter the umbra. But totality starts about the time in NZ that the moon sets and the Sun rises. Most of the total part of the eclipse is visible from eastern Australia, all of it from Western Australia. Further north almost all of Asia gets a view as does Africa.

The path of the moon through the Earth’s shadow is more nearly central than for the first eclipse of 2018. Consequently the duration of totality is greater at nearly an hour and three quarters.

Solar eclipses of 2018

The solar eclipses of 2018 are partial and of little interest to observers in Australia and New Zealand.

Partial eclipse of 2018 February 15

The first partial solar eclipse on 2018 February 15 is over the Southern Ocean and most of Antarctica. No part is visible from New Zealand nor Australia. The centre path of the eclipse, nominally annular, misses the Earth altogether.

Partial eclipse of 2018 July 13

The second partial, July 13, is a very paltry affair. Only the northern edge of the eclipse briefly touches the Earth, covering a small area mostly south of Australia and New Zealand. For Australia it does include the southern half of Victoria and the extreme south of Southern Australia southwards from Adelaide. Tasmania is inside the eclipse path. Stewart Island is also just inside the eclipse. The edge of the eclipse lies just north of the Island. The edge of the eclipse also clips the extreme southwest of the South Island.

The percentages of the Sun’s diameter obscured are very small. Adelaide is on the edge of the path, only 0.1% of the Sun being covered. Melbourne “sees” a little more, 2.3% of the sun being obscured. Hobart is deeper into the eclipse with 9.5% coverage. From South Cape on Stewart Island 1.4% of the Sun’s diameter will be hidden, an amount decreasing further north on the Island to zero at the most northerly point.

Partial eclipse of 2018 August 11

The third partial solar eclipse occurs in the northern hemisphere, mostly in the Arctic. It includes Greenland, Iceland, the extreme north of Scotland, most of Scandinavia, north and northeast Russia. Much of China, Mongolia and Siberia will see something of the eclipse. From Beijing a maximum of just over one-third of the Sun will be covered while from Okhotsk in northeast Siberia a maximum of two-thirds will be obscured as the Sun sets.

The path of totality misses the Earth completely.

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 as have the diagrams showing regions of visibility of the Solar eclipses.