Lunar eclipses can occur because the monthly orbital path of the Moon can sometimes cause the lunar disk to disappear for a short time behind the projected shadow of the Earth. Therefore they will only occur during a few hours or so around the time of Full Moon. Unlike the solar eclipses, lunar eclipses are slightly more common because of the greater apparent size of the Earth’s shadow. As such, lunar eclipses occur on average roughly once or twice each yearly, with at least one occurring in the same part of the world once every one, two to three years.
Duration of any lunar eclipse can last as long as two hours fifty minutes, with the totality lasting about half of this, or one hour forty minutes.
Components of the shadows appear as two distinct parts. These are namely the umbra and penumbra, and thirdly, the graduated shadow boundary that lies between the umbra and penumbral - the eclipse terminator.
Figure 3.1 showing the path of the Moon as it enters and exits the Earth’s shadow during a total lunar eclipse.
1) The umbra is the darkest portion seen during lunar eclipses. When the Moon passes through this shadow, it does not completely disappear, as the light from the Earth’s atmosphere refracts onto the surface of the Moon. This gives the Moon some illumination, making the umbra colour is usually as dull brick red to deep red, with the depth of colour only depending on the distance between Earth and Moon. This is also related to the lunar distance when immersed within the shadow. As such, the orbital inclination of the Moon does not always travel through the mid-point of the shadow, so we see only a partial lunar eclipse.
2) The penumbra is produced by the secondary shadow of the Earth as projected onto the Moon. The best way to imagine how it is produced, is to see it from the Moon’s perspective. There the Sun would appear partially obscured or eclipsed by the bulk of the Earth, causing the amount of light we see to slight drop in intensity compared to the brightness of Full Moon. It is usually impossible to see this visually, unless you know about the event beforehand. Penumbral eclipses can only be observed with suitable electronic light-sensitive equipment, and can be seen during the partial lunar eclipse phase, or even just before or after each total lunar eclipse.
3) Dividing the line between the umbra and penumbra is the thin transitional region that sometimes appears as odd-looking colour bands. Some of these shadow bands maybe seem grey, but sometimes they appear like the familiar colours of the rainbow, except they are in the reverse order.
Each lunar eclipse path is seen from by about half the sphere of the Earth. Often daylight will intervene, and this may reduce this percentage of the Earth that sees it considerably.
Depending where the Moon is in its orbit, determines the eclipse phase observed, and this varies from lunar eclipse to lunar eclipse. Deviation of this intersection path are due to the 5½o inclination of the orbit of the Moon.
Where the lunar path crosses the projected shadow of the Earth can vary also in angle. This depends on the location of the Moon at the time of the eclipse on the ecliptic. (As in the example of Figure 3.1, the angle shown is the high inclined in the sky.)
When the Moon happens to be at the place where the lunar orbit intersects the ecliptic, the path will cross the centre of the umbral shadow. Such lunar eclipses at mid-eclipse will often appear very dark deep-red, where in city skies can even cause the Moon to almost disappear to the naked-eye. (Colour seen in deep lunar eclipses are also affected by the distance between Earth and Moon, which will appear darker if the Moon is also near perigee.)
If the Moon passes above or below the centre of the Earth’s shadow, then this will produce either paler red coloured total lunar eclipse or just partial eclipses.
From the Moon during any total lunar eclipse, you would see the jet-black disk surrounded by a deep red ring. The true cause of the red colour is the atmosphere illumination of the Earth by the refraction of sunlight, with the entire ring being the observation of every sunrise and sunset happening then on Earth. Furthermore, the brightness of the red ring is the same red colour all observers see over the lunar surface. Anywhere away from mid-eclipse, this brilliant ring would instead appear as one slow moving arc as it travels very slowly around the disk of the Earth.
| 2008 - 2015 | |||||
| DATE Eclipse |
Eclipse Type |
Duration hh mm |
Geographic Region of Eclipse Visibility | ||
| 21st Feb 2008 | Total | 00h 51m | Central Pacific, Americas, Europe, Africa | ||
| 16th Aug 2008 | Partial | -- | South America, Europe, Africa, Asia, Australia | ||
| 09th Feb 2009 | Penumbral | -- | Eastern Europe, Asia, Australia, Pacific. | ||
| 07th Jul 2009 | Penumbral | -- | Australia, Pacific, Americas | ||
| 06th Aug 2009 | Penumbral | -- | Americas, Europe, Africa, West Asia | ||
| 31st Dec 2009 | Partial | 01h 02m | Europe, Africa, Asia, Australia | ||
| 26th June 2010 | Partial | 02h 44m | Eastern Asia, Australia, Pacific, West Americas | ||
| 21st Dec 2010 | Total | 03h 29m 01h 13mT |
Eastern Asia, Australia, Pacific, Americas, Europe | ||
| 15th June 2011 | Total | 03h 40m 01h 41mT |
South America, Europe, Australia, Africa | ||
| 10th Dec 2011 | Total | 03h 33m 01h 41mT |
Europe, East Africa, Asia, Australia | ||
| 04th June 2012 | Partial | 02h 08m | Asia, Australia, Pacific, Americas | ||
| 28th Nov 2012 | Penumbral | -- | Europe, East Africa, Asia, Australia | ||
| 25th April 2013 | Partial | 00h 32m | Europe, Africa, Asia, Australia | ||
| 25th May 2013 | Penumbral | -- | Americas, Africa | ||
| 18th Oct 2013 | Penumbral | -- | Americas, Europe, Africa | ||
| 15th April 2014 | Total | 03h 35m 01h 19mT |
Australia, Pacific, Americas | ||
| 08th Oct 2014 | Total | 03h 20m 01h 00mT |
Asia, Australia, Pacific, Americas | ||
| 04th Apr 2015 | Total | 03h 30m 00h 12mT |
Asia, Australia, Pacific, Americas | ||
| 28th Sep 2015 | Total | 03h 21m 01h 13mT |
E. Pacific Americas, Europe, Africa | ||
| T = Length of Totality | |||||
NOTE : The lines coloured light lime green are eclipses visible somewhere in Australia.
The user applying this data for any purpose forgoes any liability against the author. None of the information should be used for either legal or medical purposes. Although the data is accurate as possible some errors might be present. The onus of its use is placed solely with the user.
