On a Saturday evening in Jerusalem 2,000 years ago, a man anxiously looks upward, seeing a bright star rising in the east, and a second one overhead. Turning Northwest, he glimpses Capella in the gathering darkness. "That's it!" Three stars have appeared, and the Sabbath has ended.

The Jewish tradition of sighting stars dates back to the dawn of sky watching. Our interest in the night sky has a spiritual component, whether it is sighting the three stars or following the phases of the Moon.

I realized this on a Yom Kippur night. The beautifully moving Kol Nidre liturgy’s notes soar on high, but for me, its meaning extends to the sky. Walking home on Yom Kippur night, the bright gibbous moon dominated the evening sky, its Copernicus and Tycho craters having just seen sunrise after a frigid two-week night. Displaying the same face every Kol Nidre night, the moon joins my senses of science and spirituality.

That sense runs in our family’s six generations with Montreal’s Congregation Shaar Hashomayim, meaning “Gates of Heaven.” My grandfather William Levy helped design the sanctuary in 1922.

Judaism has a spiritual sense of the sky. Our calendar is based on the Moon’s orbit, an event we celebrate with the monthly Kiddush Levana ceremony. It is no coincidence that the Moon is always 10 days old every year Yom Kippur night, nor is it by accident that the total lunar eclipse in April this year occurred on the first Passover seder, which is always on the full Moon. This spring's eclipse is one of several I’ve seen on the first night of Passover; in 1968 I rushed from a seder early to catch one.

A culture so closely connected to the sky goes deeper than the moon phases. The first book of Chronicles describes what could be the comet of 971 BCE, protesting an ill-advised census by King David. The biblical passage is read at the seder: "David lifted his eyes, and saw the angel of G-d between earth and heaven, a drawn sword in his hand stretched out over Jerusalem."

Connecting our liturgy to a love of the sky is easy. "The Heavens declare the glory of G-d," trumpets Psalm 19; words prominently inscribed on the Stellafane clubhouse through 60 years of telescope conferences. Although not “religious,” founder Russell Porter took those words seriously. Porter’s biography notes that "One Sunday morning when he and Oscar Marshall headed for the clubhouse, they were approached by a deacon who asked if they were going to church. Porter reminded the deacon of the inscription on the gable of their temple to the stars." Years later and a continent away, he built the Palomar telescope that the Shoemakers and I used to pursue comets.

In 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, I cherished that minute as the opening shutter cajoled the sky to enter. I am sure that many skywatchers, regardless of their religious feelings, have a spiritual experience at the start of a beautiful night.

Equations explain the physics of what we see in the night sky, but the wonder goes beyond the numbers. We each have a personal reason for enjoying the precious beauty of the night sky. For some, the background of religious liturgy helps. The Jewish framework is its ancient calendar that revolves around the Moon.

The man in Jerusalem watching the sky darken felt his cosmic role. Sabbath would not end until the sky presented him with three stars; a singular, personal way to relate with the sky. Seeing that third star must have felt as wonderful as discovering a comet.

(c) Sky & Telescope, 1994 Sky&Telescope columnist David H. Levy discovered or co-discovered 21 comets, including Comet Shoemaker-Levy 9 that crashed into Jupiter the summer of 1994.
Reprinted with permission of Sky & Telescope © 1996