On Thursday night, May 15–16, the full Moon will pass through the northern part of the Earth’s
shadow, providing a colorful spectacle for observers throughout the Americas, Europe, and Africa.
Lunar eclipses get their colorful red-orange hues from sunlight that is filtered and bent by
the Earth’s atmosphere before it reaches the Moon. Skywatcher Mary Ward of Dublin, Ireland,
once likened the totally eclipsed Moon to a "red-hot penny" in the star-filled sky — a
description as apt today as it was for her on February 7, 1860.
For observers in South America on May 15–16, the total phase coincides with the Moon being high
overhead at midnight. In western North America the eclipse will already be under way as
darkness falls on May 15th, while east of the Mississippi River the entire event can be seen
later in the evening. Those in Western Europe can see the eclipse’s beginning as dawn
approaches, but its end will be swallowed up by the gathering glow.
Total Eclipse of the Moon, May 1516, 2003|
|Moon enters penumbra||1:05|| 9:05 p.m.|| 8:05 p.m.||--||--|
|Partial eclipse begins||2:03||10:03 p.m.|| 9:03 p.m.|| 8:03 p.m.||--|
|Total eclipse begins||3:14||11:14 p.m.||10:14 p.m.|| 9:14 p.m.|| 8:14 p.m.|
|Mideclipse||3:40||11:40 p.m.||10:40 p.m.|| 9:40 p.m.|| 8:40 p.m.|
|Total eclipse ends||4:06||12:06 a.m.||11:06 p.m.||10:06 p.m.|| 9:06 p.m.|
|Partial eclipse ends||5:17|| 1:17 a.m.||12:17 a.m.||11:17 p.m.||10:17 p.m.|
|Moon leaves penumbra||6:15|| 2:15 a.m.|| 1:15 a.m.||12:15 a.m.||11:15 p.m.|
One worthwhile project for skywatchers is to estimate the Moon’s stellar magnitude at mideclipse,
an excellent gauge of the sullying effect that recent volcanic eruptions, even large wildfires,
may have had on our atmosphere’s transparency. During the legendary dark eclipse of December
30, 1963, Kansas amateur James Starbird almost lost sight of the eclipsed Moon, saying it was
"like a nebula of the same magnitude as the Beehive cluster." Typically, however, the Moon
remains brighter than any nighttime star.
People who wear thick eyeglasses can simply take them off, turning the Moon and bright stars or
planets into blobs of equal size for easy comparison. For example, the Moon may or may not
outshine Antares, which is magnitude +1.1 and just 16° to its east. Jupiter (magnitude –2.0)
will be low in the western sky during this event for North America. The rising planet Mars
(magnitude –0.3) will be a convenient reference beacon for Europeans before dawn.
Also be on the lookout for anomalous colors or shadows within the umbra, like the dusky
"isosceles triangle" that English astronomer J. L. E. Dreyer noticed with the naked eye during
the January 28, 1888, eclipse.
A digital camera mounted behind a telescope’s eyepiece can snap fine close-ups of the eclipse’s
partial phases. But a fixed camera capable of multiple exposures on a single frame of film is
ideal for recording an eclipse sequence. Simply press the shutter every five minutes or so.
You’ll need a wide-angle lens, of course, because the Moon will travel 45° across the sky
between the first and last contacts with the umbra. Turn off the camera’s automatic metering
system, if any. With ISO 400 film you might try ¼ second at f/8 for the partial phases,
boosting the exposure to 3 seconds at f/4 during totality.
Sky & Telescope welcomes images of this lunar eclipse (as well as the annular eclipse on May
31st) for possible publication. Just describe clearly what you did so it can be explained in a
caption for the benefit of our readers.
As the much-dimmed Moon makes its way across the stars of Libra, observers with backyard
telescopes will be able to watch it cover and uncover many faint stars. For example,
5.5-magnitude ZC 2217 will be occulted north of a line from Montana to southern Florida (see
the map in the online article "Lunar Occultation Highlights for 2003").
If you're interested in making careful timings of individual craters and other features as they
enter or leave the umbra, please refer to the article "May's Two Eclipses" on page 104 of the
May issue of Sky & Telescope.
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Sky & Telescope senior editor Roger Sinnott will be observing this eclipse from the comfort of
his backyard in a Boston suburb.
Related Links: NASA's Goddard Space Flight Center