WONDERFUL TOTAL ECLIPSE OF THE MOON NEXT FRIDAY
Next Friday evening, July 27, there will be a total eclipse of the Moon.
Eclipses of the Moon occur when the Full Moon passes through the cone of
shadow cast by the Earth into space. Weather permitting this will be an
fascinating event to watch from the UK because the Moon will rise totally
eclipsed, giving plenty of opportunities for stunning images of a 'ghostly
red Moon' above buildings and the landscape.
Moreover, this lunar eclipse is happening on the same night that Mars comes
to opposition (its best since 2003), with the brilliant Red Planet (at
magnitude -2.8 even brighter than Jupiter) lying just below the totally
eclipsed Moon. A blood red Moon near a stunning red Mars will surely make
this an event to remember!
A SPECTACULAR MOONRISE
The lunar eclipse begins at 17:15 UT (18:15 BST) when the Moon enters the
fainter outer part of the Earth's shadow known as the penumbra. The main
phase of the eclipse begins at 18:24 UT (19:24 BST) when the Moon first
enters the central, dark part of the Earth's shadow known as the umbra. The
eclipse becomes total at 19:30 UT (20:30 BST) and lasts for a full 1 hour 43
minutes (almost the maximum possible and the longest total lunar eclipse of
the 21st century), but from the UK the Moon will not rise until totality is
well underway, so the earlier phases of the spectacle will not be visible.
Maximum eclipse is at 20:22 UT (21:22 BST), and the Moon will have risen
from most parts of the British Isles (apart from the north and west of
Scotland and Northern Ireland) by this time
The exact time at which the totally eclipsed Moon will rise above the
south-eastern horizon on Friday evening varies from place to place as shown
below:
TIMES OF MOONRISE ON JULY 27
Brighton, 19:47 UT (20:47 BST)
London, 19:49 UT (20:49 BST)
Birmingham, 20:00 UT (21:00 BST)
Plymouth, 20:01 (21:01 BST)
Cardiff, 20:02 UT (21:02 BST)
York, 20:04 UT (21:04 BST)
Manchester, 20:06 UT (21:06 BST)
Newcastle-upon-Tyne, 20:11 UT (21:11 BST)
Dublin, 20:22 UT (21:22 BST)
Edinburgh, 20:22 UT (21:22 BST)
Glasgow, 20:26 UT (21:26 BST)
Belfast, 20:27 UT (21:27 BST)
TOTALITY
The visibility and appearance of the totally eclipsed Moon at moonrise will
depend on how clear the south-eastern sky is from your location at the time.
With the naked eye, the Moon may well not be discernible until it has risen
a few degrees above the local horizon, but with binoculars or a telescope it
will be seen more easily. It is while the Moon is still low in the sky that
there should be plenty of possibilities for interesting images. The BAA's
Lunar Section, Journal Editor and Website Manager would welcome such images.
The total phase of the eclipse ends at 21:13 UT (22:13 BST). As the Moon
will be passing centrally through the Earth's umbral shadow, it is probable
that the Moon may appear quite dark during mid-totality but one never quite
knows how dark or how bright a lunar eclipse will be. Everything depends on
the conditions in the Earth's upper atmosphere through which all light
falling onto the shadowed Moon has to pass. There have been eclipses when
the Moon has been difficult to find even with a telescope, while at other
eclipses it has remained bright red or vividly coloured. The Moon appears a
reddish hue because of Rayleigh scattering - the same effect that causes
sunrises and sunsets to appear reddish - and the refraction of that light by
the Earth's atmosphere into its umbral shadow.
The partial eclipse ends at 22:19 UT (23:19 BST), when the Moon exits the
umbra. The faint penumbral phase finally ends at 23:28 UT (00:28 BST on July
28).
This will be the first central lunar eclipse (i.e. passing through the
centre of the Earth's umbral shadow since 2011 June 15, with the Moon in
Capricornus and very near apogee, its furthest distance from the Earth. The
Moon's apparent diameter will be 29' 26.6".
ONE OF THREE...
Such an eclipse of the Moon never comes unaccompanied. A solar eclipse
always occurs about two weeks before or after a lunar eclipse. Usually,
there are two eclipses in a row, but sometimes there are three in the same
eclipse season. This is the second eclipse of the season. The first, a
partial solar eclipse on 2018 July 13, could be seen only from a very small
part of northern Antarctica and the third, another partial solar eclipse on
2018 August 11, will be seen from the far northern and eastern parts of
Europe, northern parts of North America and some northern and western
locations in Asia.
Some further information on this Friday's eclipse may be found on page 14 of
the 2018 BAA Handbook, and also at:
https://eclipse.gsfc.nasa.gov/LEplot/LEplot2001/LE2018Jul27T.pdf
Please send any images or other observations of this event to the BAA Lunar
Section.
This e-bulletin issued by:
Dr John Mason
BAA Press and Publicity Officer
2018 July 22
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