Start
your day with an eclipse of the full Moon! On the morning of October
8, 2014, a total lunar eclipse will be visible across most of North
America.
Were
approaching the second of four total lunar eclipses that come at
half-year intervals in 2014 and 2015: a lunar-eclipse tetrad. All
four can be seen from at least parts of North America.
The one before dawn on
Wednesday, October 8th, will be visible from nearly all of the Americas.
Moreover, the Moon, two days after perigee, will be 5% larger in
diameter than it was during the
first eclipse of the tetrad on April 14-15 earlier this year.
The map, diagram, and
timetable below will tell what to expect at your location and when.
If youre in the central or western parts of the U.S. and Canada,
youll see the total eclipse high in a dark sky well before
sunrise. Easterners will find dawn brightening and the Moon sinking
low in the west while the eclipse is in progress offering
particularly interesting photo opportunities. Viewers in Australia
and eastern Asia get to view this event on the evening of October
8th.
How to Watch
the Lunar Eclipse
A
total lunar eclipse has five stages, with different things to watch
during each interval over a roughly 3-hour period.
The first penumbral
stage begins when the Moons leading edge enters the pale
outer fringe of Earths shadow, the penumbra. But the shading
is so weak that you wont notice anything until the Moon has
intruded about halfway into the penumbra. Watch for a slight darkening
to become apparent on the Moons celestial eastern side. The
penumbral shading becomes stronger as the minutes tick off and the
Moon moves deeper in.
The second stage is partial
eclipse. This begins much more dramatically when the Moons
leading (eastern) edge enters the umbra, Earths central shadow,
where no direct sunlight reaches. With a telescope, you can watch
the edge of the umbra slowly engulfing one lunar feature after another,
as the entire sky grows darker and darker.
An hour or so into partial
eclipse, only a final bright sliver of Moon remains outside the
umbra. And the rest is already showing an eerie reddish glow.
The third stage is the
total eclipse itself, or totality, beginning when the last
rim of Moon slips into the umbra. Although the Sun here is completely
hidden, the Moon is sure to glow some shade of orange or red. This
red light on the Moon is sunlight skimming and bending through Earths
atmosphere: its the light of all the sunrises and sunsets
that ring our world at any given moment. An astronaut standing on
the Moon would see the Sun hidden and the dark Earth ringed with
sunset- and sunrise-colored brilliance.
On rare occasions the
eclipsed Moon does go almost black. Other times it appears as bright
as a fresh penny. Sometimes it turns brown like milk chocolate.
Two factors affect an
eclipses color and brightness. The first is simply how deeply
the Moon goes into the umbra; the umbras center is much darker
than its edges.
The other factor is the
state of Earths atmosphere along the sunrise-sunset line.
If the air is very clear, the eclipse is bright. But if a major
volcanic eruption has recently polluted the stratosphere with thin
global haze, the eclipse will be dark red, ashen gray, or almost
black.
In addition, blue light
refracted by Earths clear, ozone-rich upper atmosphere can
also add to the scene, especially near the umbras edge, creating
a subtle mix of changing colors. Time-lapse videos might show large
flying shadows in the umbra, caused by changing cloud-shadowing
effects around the sunrise-sunset line as Earth turns.
Totality on October 14th
lasts 59 minutes. And then, as the Moon continues eastward along
its orbit, events replay in reverse order. The Moons leading
edge reemerges into sunlight, ending totality and beginning stage
four: partial eclipse again.
When the entire Moon
escapes the umbra, only the last penumbral shading remains
for stage five. This final duskiness slowly fades away, leaving
the full Moon as bright as ever.
ECLIPSE EVENT |
EDT
|
CDT
|
MDT
|
PDT
|
Penumbra first visible |
4:45 a.m.
|
3:45 a.m.
|
2:45 a.m.
|
1:45 a.m.
|
Partial eclipse begins |
5:15 a.m.
|
4:15 a.m.
|
3:15 a.m.
|
2:15 a.m.
|
Total eclipse begins |
6:25 a.m.
|
5:25 a.m.
|
4:25 a.m.
|
3:35 a.m.
|
Mid-eclipse |
6:55 a.m.
|
5:55 a.m.
|
4:55 a.m.
|
3:55 a.m.
|
Total eclipse ends |
7:24 a.m.
|
6:24 a.m.
|
5:24 a.m.
|
4:24 a.m.
|
Partial eclipse ends |
|
7:34 a.m.
|
6:34 a.m.
|
5:34 a.m.
|
Penumbra last visible? |
|
|
7:05 a.m.
|
6:05 a.m.
|
How To Photograph
the Lunar Eclipse
With the prospect of
the Moon changing from bright to dull red-orange and back again,
don't overlook the possibility of recording this dramatic celestial
event with your still or video camera! Photographing a total lunar
eclipse isn't difficult but it does take a little preparation.
Most
importantly, you'll need a telescope or telephoto lens that enlarges
the Moon to a good size. The minimum focal length for getting a
good-looking Moon is about 300 mm. You'll also need a tripod to
keep your camera rock-steady, or you can piggyback your camera on
a tracking telescope mount.
Because the coloration
and brightness of eclipsed Moon is different every time it plunges
through the umbra and even during totality itself
the best advice for photographing a lunar eclipse is to take lots
of pictures at many different exposures. Count on using times of
½ second or longer during totality, so make sure your camera
is able to make exposures that long, preferably in "manual"
mode. Use a remote control (or the self-timer function) to minimize
vibration during the exposures.
S&T's imaging experts
offer more great tips on how
to photograph a lunar eclipse elsewhere on this web site.
Uranus Too!
By
quite a coincidence the planet Uranus, just one day past opposition
and thus shining its brightest at magnitude 5.7, will appear only
about 1° from the Moon during totality. Spot it in binoculars
using the finder chart at right.
The actual position of
the eclipsed Moon against the starry background in Pisces will depend
slightly on where you are and the stage of the eclipse. The Moon
on the chart is positioned for the middle of North America at the
start of totality, but elsewhere the difference won't be more than
a couple of Moon diameters at most. You should have no trouble finding
the 4½-magnitude stars Epsilon (e) and Delta (d) Piscium
north of the Moon. Identify Uranus by the shape of the triangle
it makes with those two stars.
Can you see anything
of Uranus's aquamarine blue-green tint? Color contrast with the
vivid orange-red Moon might make this more apparent. In a telescope,
Uranus is a tiny disk 3.7 arcseconds wide. It's 2.6 light-hours
from Earth, compared to the Moon's distance of 1.2 light-seconds.
|