THE SOUTHWORTH PLANETARIUM
70 Falmouth Street      Portland, Maine 04103
(207) 780-4249      usm.maine.edu/planet
43.6667° N    70.2667° W  Altitude:  10 feet below sea level Founded
January 1970
2021-2022: LXII
"You have power over your mind - not outside events. Realize this and you
will find strength."
-Marcus Aurelius


THE DAILY ASTRONOMER Monday, January 10, 2022
The May 2022 Lunar Eclipse Part I

Today we look into a warm, vibrant and lovely future: namely, into mid-May,
the time of year when the nordic wind spirits finally retreat to the
hinterlands and spring truly begins. This year, not only will mid-May offer
us an abundance of bone-thawing warmth, we'll also experience a total lunar
eclipse! Weather permitting, we shall see the entire event here. The
Southworth Planetarium will be open for this event and so we want to be
sure that everybody knows about it, hence this early alert. This article
will provide subscribers with a time-table specific to Portland (ME).
Tomorrow's article answers questions about the lunar eclipse: both general
information and that specific to the May 2022 event.

First, the eclipse will occur on the night of May 15th. Actually, it will
begin on May 15th and end on May 16th. Refer to the time table below.

*May 15 - 9:32 p.m. PENUMBRAL ECLIPSE BEGINS*
Earth's shadow is divided into two regions: the light, outer part of Earth's
shadow, called the 'penumbra,' and the inner region called the 'umbra.' The
penumbral eclipse begins when Earth first touches the penumbra. The moon
passes completely into the penumbra before it reaches the umbra. Honestly,
unless you're one of those mystical poetic types who can actually tell the
difference between a whisper of a breeze and a caressing zephyr, you won't
notice much during the penumbral part of a lunar eclipse. Perhaps the
brilliant moon's pallor is rendered a few phantoms less vibrant, but even
that is a stretch.

*May 15    -    10:27 p.m. PARTIAL ECLIPSE BEGINS*
This is when the 'action' starts. The umbra is the dark interior shadow.
Once the umbral eclipse begins, we'll see Earth's curved shadow against the
moon. We'll watch the shadow migrate across the moon until the moon is
completely immersed in Earth's shadow.

*May 15    -    11:29 p.m. TOTALITY BEGINS*
Totality begins when the moon is completed inside Earth's umbra. The moon
will not be wholly lost from sight. Instead it will appear reddish, because
Earth's atmosphere scatters blue light, but directs red light into its
shadow. (We see a blue sky during the sky because of this effect.) The
eclipsed moon will reflect this reddish light back to us, producing the
ominously named 'blood' moon. One effect that we think is absolutely
magnificent is the 'spherical moon' phenomenon. During totality, the color
differential across the moon's facade lends it a spherical appearance. The
moon actually appears as a crimson sphere in space, as opposed to the full
moon's usual disc-like appearance.

*May 16    -    12:11 a.m.   MAXIMUM ECLIPSE*
When the distance separating the center of the shadow and the moon's center
is at a minimum.

*May 16   -   12:53 a.m.       TOTALITY ENDS*
At this moment, the moon starts its exit from the umbra.  We will see a
thin sliver of the moon emerging from the inner shadow.

*May 16  -    1:55 a.m.    UMBRAL ECLIPSE ENDS*
For all intents and purposes, the show is now over.  The moon completely
leaves the umbra and appears, well, like a full moon again, except that it
remains immersed in the penumbra.

*May 16 -    2:50 a.m.    PENUMBRAL ECLIPSE ENDS*
The eclipse event is now technically over.  Of course, the moon's
brightness is hardly diminished during this last hour because the penumbra
is so faint.

Tomorrow, we present more information about what promises to be a beautiful
mid-May lunar eclipse.



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