Post by tanath on Mar 1, 2007 0:44:49 GMT -5
Almost 2-1/2 years have passed since the Moon plunged completely into the E
arth's shadow. But if you live in Europe, Africa, or the eastern half of North
America, but sure to put a big circle on your calendar for Saturday, March
3.
Unlike an eclipse of the Sun which often requires a long journey to the path
of totality, those of the Moon can be observed from one's own backyard. The
passage of the Moon through the Earth's shadow is equally visible from all
places within the hemisphere where the Moon is above the local horizon.
Moreover, coming as it does early on a Saturday evening, this eclipse should
arouse wide interest among tens of millions of people in the eastern parts of the
United States and Canada who can see it during normal waking hours.
Astronomy clubs might take this opportunity to alert schools and the
mainstream media about their eclipse activities and amateur astronomy in general.
Why not consider throwing a neighborhood eclipse party?
Images: The Moon / Eclipse 2003 / Eclipse 2004
The timing
The beginning and ending of a lunar eclipse happens simultaneously for every
viewer, unlike an eclipse of the Sun. The total phase of the eclipse begins
at 5:44 p.m. EST (22:44 GMT) and ends at 6:58 p.m. EST (23:58 GMT). A
timetable, plus graphics showing how an eclipse works, is available at SPACE.Com.
Europe and Africa are in the best position; the eclipse will happen during
the late-night hours of March 3-4, with the Moon high in the sky. From
Newfoundland and Labrador will see the Moon rise prior to its entrance into the
umbra (6:00 p.m. Newfoundland Time). For the rest of North America, the eclipse
will already in progress when the Moon rises.
Unfortunately, for those living in the western United States and Canada, the
eclipse will have pretty much ended by the time the Moon rises. As a
consolation, however, the next total eclipse later this year (on Aug. 27) will
favor these locations.
For many of us a total eclipse of the Moon can be enjoyed purely as a
spectacle, a means of appreciating nature in an unfamiliar guise. But many kinds
of careful observations can have scientific interest. Even with the unaided
eye a lunar eclipse is pleasing to watch, but binoculars will certainly
improve the view. For visual observations, a small telescope is recommended. You
should use your lowest-power eyepiece.
The total phase
This week we will concentrate solely on viewing the Moon during the total
phase of the eclipse. During the 74 minutes that the Moon is completely
immersed in the Earth's dark umbral shadow, the big question will be how it will
appear in the sky. Some eclipses are such a dark blackish-gray that the Moon
nearly vanishes from view. At other eclipses it may seem to glow like a
bright orange ember.
The reason that the Moon can be seen at all during totality is that sunlight
is scattered and refracted around the edge of the Earth by our atmosphere.
If an astronaut were standing on the Moon's surface during totality, the Sun
would be hidden behind a dark Earth, appearing roughly four-times larger than
the Sun and rimmed by a brilliant reddish ring of all the world's sunrises
and sunsets.
How bright this ring around the Earth appears is dependant on global weather
conditions and the amount of dust suspended in the air. A clear atmosphere
on Earth means a bright lunar eclipse. But if a major volcanic eruption has
recently injected particles into the stratosphere, the eclipse will likely be
very dark. No such eruptions have happened in recent years, so the betting
is that the Moon will appear fairly bright.
The Moon will track through the northern part of the Earth's shadow. The
Moon's orientation as seen from eastern Canada and the U.S., means that its
left portion should appear brightest, as that that will be the part of the Moon
nearest to the shadow's edge. There may be a gradation in hue between the
parts of the disk nearest and farthest from the shadow center.
A careful description of the colors seen on the eclipsed Moon and their
changes is valuable. The hues depend on the optical equipment used, usually
appearing more vivid with the naked eye than in telescopes. The French
astronomer, Andre Danjon introduced the following five-point scale of lunar luminosity
('L') to classify eclipses:L = 0: Very dark eclipse, Moon almost invisible,
especially in mid-totality. L = 1: Dark eclipse, gray or brownish
coloration, details distinguishable only with difficulty. L = 2: Deep red or
rust-colored eclipse, with a very dark central part in the shadow, and outer edge
of the umbra relatively bright. L = 3: Brick red eclipse, usually with a
bright or yellow rim to the shadow. L = 4: Very bright copper-red or orange
eclipse, with a bluish very bright shadow rim.
Examine the Moon at mid-totality and also near the beginning and end of
totality to get an impression of both the inner and outer umbra. In noting an L
observation, state the time and optical means used.
Impressive darkness
At mid-totality, the darkness of the sky is impressive. Faint stars appear,
and the surrounding landscape takes on a somber hue. As totality ends, the
eastern edge of the Moon begins to emerge from the umbra, and the sequence of
events repeats in reverse order until the spectacle is over.
Another procedure is to estimate the stellar magnitude of the Moon during
totality. When it's faintest, at mid-totality, the Moon may be similar in
brightness to naked-eye planets or prominent stars. To see the Moon and stars as
comparable disks, some nearsighted observers need only remove their glasses.
Another technique is to view both the eclipsed Moon and comparison stars
simultaneously through binoculars held backwards, so that the large objective
lenses are nearest the eyes.
I would like to invite readers to e-mail me with their observations
concerning the color and brightness of the eclipse. Send me your L-estimate (be sure
to give your location, as well as note the time you made your observation,
and what instrument, if any, you used). Also try to make an estimation of the
brightness of the Moon compared with bright stars and planets.
Editor's Note: On Friday, March 2, Joe Rao's weekly Night Sky column will go
into greater details on the special circumstances of trying to view a lunar
eclipse at moonrise.
More about the Moon Top 10 Luna-Terms Top 10 Cool Moon Facts Skywatcher's
Guide to the Moon Why Does the Moon Look Bigger on the Horizon? More Lunar
News, Facts and Lore
Basic Sky GuidesAstrophotogra phy 101 Sky Calendar & Moon Phases 10 Steps to
Rewarding Stargazing More Skywatching News & Features
Joe Rao serves as an instructor and guest lecturer at New York's Hayden
Planetarium. He writes about astronomy for The New York Times and other
publications, and he is also an on-camera meteorologist for News 12 Westchester, New
York. Original Story: Viewer's Guide: March 3 Total Lunar Eclipse
Visit SPACE.com and explore our huge collection of Space Pictures, Space
Videos, Space Image of the Day, Hot Topics, Top 10s, Multimedia, Trivia, Voting
and Amazing Images. Follow the latest developments in the search for life in
our universe in our SETI: Search for Life section. Join the community, sign
up for our free daily email newsletter, listen to our Podcasts, check out our
RSS feeds and other Reader Favorites today!
Copyright © 2007 _SPACE.com_
(http://us.rd. yahoo.com/ dailynews/ space/SIG= grdpua;_ylt= As_w757Q7nhOHOXI G0lPihD737YB/ *http://www. SPACE.com/) .
arth's shadow. But if you live in Europe, Africa, or the eastern half of North
America, but sure to put a big circle on your calendar for Saturday, March
3.
Unlike an eclipse of the Sun which often requires a long journey to the path
of totality, those of the Moon can be observed from one's own backyard. The
passage of the Moon through the Earth's shadow is equally visible from all
places within the hemisphere where the Moon is above the local horizon.
Moreover, coming as it does early on a Saturday evening, this eclipse should
arouse wide interest among tens of millions of people in the eastern parts of the
United States and Canada who can see it during normal waking hours.
Astronomy clubs might take this opportunity to alert schools and the
mainstream media about their eclipse activities and amateur astronomy in general.
Why not consider throwing a neighborhood eclipse party?
Images: The Moon / Eclipse 2003 / Eclipse 2004
The timing
The beginning and ending of a lunar eclipse happens simultaneously for every
viewer, unlike an eclipse of the Sun. The total phase of the eclipse begins
at 5:44 p.m. EST (22:44 GMT) and ends at 6:58 p.m. EST (23:58 GMT). A
timetable, plus graphics showing how an eclipse works, is available at SPACE.Com.
Europe and Africa are in the best position; the eclipse will happen during
the late-night hours of March 3-4, with the Moon high in the sky. From
Newfoundland and Labrador will see the Moon rise prior to its entrance into the
umbra (6:00 p.m. Newfoundland Time). For the rest of North America, the eclipse
will already in progress when the Moon rises.
Unfortunately, for those living in the western United States and Canada, the
eclipse will have pretty much ended by the time the Moon rises. As a
consolation, however, the next total eclipse later this year (on Aug. 27) will
favor these locations.
For many of us a total eclipse of the Moon can be enjoyed purely as a
spectacle, a means of appreciating nature in an unfamiliar guise. But many kinds
of careful observations can have scientific interest. Even with the unaided
eye a lunar eclipse is pleasing to watch, but binoculars will certainly
improve the view. For visual observations, a small telescope is recommended. You
should use your lowest-power eyepiece.
The total phase
This week we will concentrate solely on viewing the Moon during the total
phase of the eclipse. During the 74 minutes that the Moon is completely
immersed in the Earth's dark umbral shadow, the big question will be how it will
appear in the sky. Some eclipses are such a dark blackish-gray that the Moon
nearly vanishes from view. At other eclipses it may seem to glow like a
bright orange ember.
The reason that the Moon can be seen at all during totality is that sunlight
is scattered and refracted around the edge of the Earth by our atmosphere.
If an astronaut were standing on the Moon's surface during totality, the Sun
would be hidden behind a dark Earth, appearing roughly four-times larger than
the Sun and rimmed by a brilliant reddish ring of all the world's sunrises
and sunsets.
How bright this ring around the Earth appears is dependant on global weather
conditions and the amount of dust suspended in the air. A clear atmosphere
on Earth means a bright lunar eclipse. But if a major volcanic eruption has
recently injected particles into the stratosphere, the eclipse will likely be
very dark. No such eruptions have happened in recent years, so the betting
is that the Moon will appear fairly bright.
The Moon will track through the northern part of the Earth's shadow. The
Moon's orientation as seen from eastern Canada and the U.S., means that its
left portion should appear brightest, as that that will be the part of the Moon
nearest to the shadow's edge. There may be a gradation in hue between the
parts of the disk nearest and farthest from the shadow center.
A careful description of the colors seen on the eclipsed Moon and their
changes is valuable. The hues depend on the optical equipment used, usually
appearing more vivid with the naked eye than in telescopes. The French
astronomer, Andre Danjon introduced the following five-point scale of lunar luminosity
('L') to classify eclipses:L = 0: Very dark eclipse, Moon almost invisible,
especially in mid-totality. L = 1: Dark eclipse, gray or brownish
coloration, details distinguishable only with difficulty. L = 2: Deep red or
rust-colored eclipse, with a very dark central part in the shadow, and outer edge
of the umbra relatively bright. L = 3: Brick red eclipse, usually with a
bright or yellow rim to the shadow. L = 4: Very bright copper-red or orange
eclipse, with a bluish very bright shadow rim.
Examine the Moon at mid-totality and also near the beginning and end of
totality to get an impression of both the inner and outer umbra. In noting an L
observation, state the time and optical means used.
Impressive darkness
At mid-totality, the darkness of the sky is impressive. Faint stars appear,
and the surrounding landscape takes on a somber hue. As totality ends, the
eastern edge of the Moon begins to emerge from the umbra, and the sequence of
events repeats in reverse order until the spectacle is over.
Another procedure is to estimate the stellar magnitude of the Moon during
totality. When it's faintest, at mid-totality, the Moon may be similar in
brightness to naked-eye planets or prominent stars. To see the Moon and stars as
comparable disks, some nearsighted observers need only remove their glasses.
Another technique is to view both the eclipsed Moon and comparison stars
simultaneously through binoculars held backwards, so that the large objective
lenses are nearest the eyes.
I would like to invite readers to e-mail me with their observations
concerning the color and brightness of the eclipse. Send me your L-estimate (be sure
to give your location, as well as note the time you made your observation,
and what instrument, if any, you used). Also try to make an estimation of the
brightness of the Moon compared with bright stars and planets.
Editor's Note: On Friday, March 2, Joe Rao's weekly Night Sky column will go
into greater details on the special circumstances of trying to view a lunar
eclipse at moonrise.
More about the Moon Top 10 Luna-Terms Top 10 Cool Moon Facts Skywatcher's
Guide to the Moon Why Does the Moon Look Bigger on the Horizon? More Lunar
News, Facts and Lore
Basic Sky GuidesAstrophotogra phy 101 Sky Calendar & Moon Phases 10 Steps to
Rewarding Stargazing More Skywatching News & Features
Joe Rao serves as an instructor and guest lecturer at New York's Hayden
Planetarium. He writes about astronomy for The New York Times and other
publications, and he is also an on-camera meteorologist for News 12 Westchester, New
York. Original Story: Viewer's Guide: March 3 Total Lunar Eclipse
Visit SPACE.com and explore our huge collection of Space Pictures, Space
Videos, Space Image of the Day, Hot Topics, Top 10s, Multimedia, Trivia, Voting
and Amazing Images. Follow the latest developments in the search for life in
our universe in our SETI: Search for Life section. Join the community, sign
up for our free daily email newsletter, listen to our Podcasts, check out our
RSS feeds and other Reader Favorites today!
Copyright © 2007 _SPACE.com_
(http://us.rd. yahoo.com/ dailynews/ space/SIG= grdpua;_ylt= As_w757Q7nhOHOXI G0lPihD737YB/ *http://www. SPACE.com/) .
thanks stormie