by Richard Ingham Richard Ingham 2 hrs 13 mins ago PARIS (AFP) – Weather permitting, skygazers in northern America and Europe are in for a treat in the early morning hours of Tuesday, when the first total lunar eclipse in almost three years is poised to turn the Moon pink, coppery or even a blood red.
Coinciding eerily with the northern hemisphere's mid-winter solstice, the eclipse will happen because the Sun, the Earth and its satellite are directly aligned, and the Moon swings into the cone of shadow cast by its mother planet.
The Moon does not become invisible, though, as there is still residual light that is deflected towards it by our atmosphere.
Most of this refracted light is in the red part of the spectrum and as a result the Moon, seen from Earth, turns a reddish, coppery or orange hue, sometimes even brownish.
"The entire event is visible from North America, Greenland and Iceland," says NASA's veteran eclipse expert Fred Espenak, pointing out that for observers in the western US and Canada, the show will start on Monday evening rather than Tuesday morning.
"Western Europe will see the beginning stages of the eclipse before moonset, while western Asia will get the later stages after moonrise."
The eclipse runs for three and a half hours, from 0633 GMT to 1001 GMT, although the stage of total eclipse -- when the Moon heads into the "umbra" cast by the Earth -- lasts from 0741 to 0853 GMT.
Two factors affect an eclipse's colour and brightness, says the US astronomy magazine Sky & Telescope.
"The first is simply how deeply the Moon goes into the umbra. The center of the umbra is much darker than its edges," it says.
"The other factor is the state of Earth's atmosphere along the sunrise-sunset line. If the air is very clear, the eclipse is bright. But if a major volcanic eruption has polluted the stratosphere with thin haze, the eclipse will be dark red, ashen gray, or blood-black."
Lunar eclipses have long been associated with superstitions and signs of ill omen, especially in battle.
The defeat of the Persian king Darius III by Alexander the Great in the Battle of Gaugamela in 331 BC was foretold by soothsayers when the Moon turned blood-red a few days earlier.
And an eclipse is credited with saving the life of Christopher Columbus and his crew when they were stranded without supplies on the coast of Jamaica.
According to legend, Columbus, looking at an astronomical almanac compiled by a German mathematician, realised that a total eclipse of the Moon would occur on February 29, 1504.
He called the native leaders and warned them if they did not help, he would make the Moon disappear the following night.
The warning, of course, came true, prompting the terrified people to beg Columbus to restore the Moon -- which he did, in return for as much food as his men needed. He and the crew were rescued on June 29, 1504.
The last total lunar eclipse took place on February 21 2008. Next year, says Espenak, will see two: on June 15 and December 10.
A solar eclipse happens when the Moon swings between the Earth and the Sun.
+ FOR FURTHER DETAILS:
- www.mreclipse.com/LEdata/TLE2010Dec21/TLE2010Dec21.html
- www.space.com/spacewatch/total-lunar-eclipse-moon-101217.html
- www.skyandtelescope.com/observing/highlights/111597159.html
And the Christian Science Monitor Says :
The lunar eclipse early Tuesday morning will be the first total lunar eclipse to occur on the Winter solstice since 1638. The Winter solstice is the shortest day of the year in the Northern Hemisphere.
The lunar eclipse early Tuesday morning will be the first total lunar eclipse to occur on the Winter solstice since 1638. The Winter solstice is the shortest day of the year in the Northern Hemisphere.
In a lunar eclipse, the Earth's shadow covers the moon. This image of the moon was taken Oct. 27, 2004 during a total lunar eclipse by a Dobsonian telescope from the Coca-Cola Space Science Center in Columbus, Ga.
(Columbus Ledger-Enquirer/ Philip Wartena/AP/File)
By
Joe Rao, Skywatching columnist, Space.com
posted December 19, 2010 at 1:58 pm EST
The upcoming Dec. 21 full moon — besides distinguishing itself from the others in 2010 by undergoing a total lunar eclipse — will also take place on the same date as the solstice (the winter solstice if you live north of the equator, and the summer solstice if you live to the south).
Winter solstice is the shortest day of the year in the Northern Hemisphere and marks the official
beginning of winter. The sun is at its lowest in our sky because the North Pole of our tilted planet is pointing away from it.
So, how often does the December full moon coincide with
the solstice? To answer this question, let's use Universal Time (UT), also sometimes referred to as Greenwich Mean Time (GMT). We do this because in answering this question, it's important to define a specific time zone.
IN PICTURES: We love the moon
For example, if you live in Honolulu, this December's full moon does not fall on the date of the solstice. Hawaii Time runs 10 hours behind GMT and the full moon occurs on Dec. 20 at 10:13 p.m. local time, while the solstice comes the following day at 1:38 p.m. Alaska, too, will have the full moon and the solstice occur on these respective dates, but in a time zone one hour later than Hawaii.
But both the full moon and solstice do occur on the same date (Dec. 21) in Greenwich, as well across the contiguous United States and Canada.
Prior to this year, there were solstice full moons in 1999 (Dec. 22) and 1980 (Dec. 21).
Interestingly, after this year, we'll have a long time to wait until we have a December full moon occur on the same date as the solstice: Dec. 21, 2094! And even more interesting – just like this year – that same full moon will fall into Earth's shadow in a
total lunar eclipse. However, unlike this year, the 2094 eclipse will not be visible from the Western Hemisphere, but will be able to be seen from Europe, Africa and much of Asia. [
How to Watch the Dec. 20 Total Lunar Eclipse]
Finally, this raises the question — prior to 2010, when was the last time that we had a total lunar eclipse occur on the same calendar date as the winter solstice? The answer, incredibly, takes us back nearly four centuries.
On Dec. 21, 1638, the full moon was in total eclipse from 1:12 to 2:47 UT. And the solstice occurred later in the day at 16:05 UT. [
Amazing photos of a total lunar eclipse]
Once again, it's important to note that this occurred at the Greenwich meridian. For the Americas, this eclipse actually occurred during the evening of Dec. 20, while the solstice occurred on the following day.
IN PICTURES: We love the moon
Posts
