Star Trails 101
--------------

The Third Star


by David H. Levy

     It's late on a Saturday afternoon in downtown
Jerusalem, perhaps 2500 years ago.  A man stands outside the
Temple, anxiously looking upward.  He sees a bright star
rising in the east, and a second one overhead.  This man
knows the sky well, and as he turns to the Northwest, he
glimpses Capella in the gathering darkness.  "That's it!" he
thinks.  Three stars have appeared, and that ancient Sabbath
of millennia ago has ended.

     Although the Jewish tradition of sighting stars is no longer
generally practiced, it dates back to the dawn of skywatching.  
On cloudy nights, the observer would look at two strings, 
one white, one blue, and would judge the sabbath over when he could no 
longer tell their colors apart. All of Judaism is based on a lunar 
calendar. For many of us, the sky goes beyond equations; 
our interest in the night sky has a strong spiritual component, 
whether it is the sighting of three stars or the phase of the Moon.  
I realized this many years ago, on the eve of Judaism's holiest day.  
Kol Nidre evening, a long and beautiful service,  is known
for some of the most soaring music of the Jewish liturgy, but
for me its meaning  extends literally to the sky.  While
walking home after one of these services, I noticed the bright
10 day old gibbous moon dominating the evening sky, its
impact craters Copernicus and Tycho having just seen
sunrise after their frigid two-week night.  I realized that the
Moon displays the same phase every Kol Nidre night, and
has through the ages.  That moonlit walk home joined my
senses of science and spirituality.  
 
     That sense of spirituality is strong in our family, six
generations of which have been with Congregation Shaar
Hashomayim.  This synagogue, whose name means Gates of
Heaven, is celebrating its 150th anniversary this year.   
William Levy, my grandfather,  helped design the sanctuary
which was built in 1922.  The synagogue is especially known
for its exquisite choir, whose renderings of  Jewish liturgical
music have made Sabbath and holiday services a joy to
attend.  When I am hunting for comets late at night, I often
think of the choir's renderings: they end so beautifully and
peacefully that they almost command  their listeners to look
up.
 
     Having a spiritual sense of the sky is not just a feeling.
In Judaism the relation is a literal one, since the calendar is
based on the orbit of the Moon about the Earth.  It is not a
coincidence that the Moon is always 10 days old every year
after Kol Nidre services, nor is it by accident that the total
lunar eclipse of April 3 this year took place on the first 
Passover seder, which always occurs on the night of full
Moon.   This spring's eclipse is one of several I have seen
during the first night of Passover; in 1968 I rushed away
from a seder early to catch one.  
 
     A culture so closely connected to the sky will go more
deeply than moon phases. The first book of Chronicles
describes what could be a comet-- the comet of 971 BC
appeared near that time-- which protested an ill-advised
census King David had ordered.   The biblical passage is
read every year at the Passover seder: "And David lifted up
his eyes, and saw the angel of the Lord standing between the
earth and the heaven, having a drawn sword in his hand
stretched out over Jerusalem."  
 
     Connecting the words of liturgy to a love of the sky is
easy, as anyone who has attended Stellafane knows. But
though the words are there, the feeling more complicated. 
"The Heavens declare the glory of God," trumpets Psalm 19;
these words remain prominently inscribed on the clubhouse
through sixty years of telescope conferences.  Russell Porter,
Stellafane's 1920s founder, took those words very seriously
even though he was not an active churchgoer.  In his
biography of Porter, Berton Willard noted that "One Sunday
morning when he and Oscar Marshall were heading for the
clubhouse, they were approached by a deacon and asked
whether they were going to church.  Porter replied they were
going to Breezy Hill and would not make any noise that
would disturb him.  He also reminded the deacon of the
inscription on the gable of their temple to the stars."  Porter
felt that there was no place closer to his spirit than an
observatory like Stellafane.  Years later and a continent
away, he built the telescope at Palomar that the Shoemakers
and I used in our comet discoveries. In all the many hours
we worked there, my favorite part was when the dome
shutters started to open, slowly revealing a darkening sky. 
No matter how busy the next 13 hours of photography would
be, I cherished the minute that passed by as the opening
shutter cajoled the sky to enter.  It is a spiritual feeling that
can separate from a specific religious belief, but doesn't have
to be, and I am sure many skywatchers, regardless of their
religious feelings, have a similar experience at the start of a
beautiful night.
 
     Equations can explain the physics of what we see in the
night sky, but the wonder goes beyond the numbers.  Each of
us has a personal reason for enjoying the precious beauty of
the night sky.  For some, the background of a religious
liturgy helps.  The Jewish framework is its ancient tradition
of a nomadic people that depended on the Moon for their
calendar.  It was also a part of that tradition that the Sabbath
and festivals ended after an official observer noticed that the
evening sky was dark enough that three stars had appeared. 
That man who stood outside the Temple in Jerusalem,
waiting with anticipation for the sky to darken so gradually
and carefully until three stars appeared, must have felt his
cosmic role.  Sabbath would not end until the sky presented
him with three stars.  It must have been a singular and
personal way to get acquainted with the sky.  Seeing that
third star must have felt as wonderful as discovering a comet.


(c) Sky & Telescope, 1996