By David H. Levy
Sleep, my child, and peace attend thee
All through the night;
Guardian angels God will send thee
All through the night.
Soft the drowsy hours are creeping,
Hill and vale in slumber sleeping,
I my loving vigil keeping,
All through the night.
While the moon her watch is keeping
All through the night;
While the weary world is sleeping
All through the night.
Over thy spirit gently stealing,
Visions of delight revealing,
Breathes a pure and holy feeling,
All through the night.
Ar Hyd y Nos (All Through the Night) Edward Jones' Musical and Poetical Relics of the Welsh Bards (1784).
I learned about this gorgeous hymn at Twin Lake Camp during the Summer of 1956. I was 8 years old. During one of the three summers I spent at Twin Lake I sang that hymn at least once at a camp assembly. The older campers were extraordinarily patient with my unfortunate voice. My favourite line, “While the moon her watch is keeping” surfaced more recently. There is a singular magic to being out of doors on a clear night and looking at the Moon. There is a sense of delight, and the result for me is indeed “a pure and holy feeling.”
The idea of the Moon keeping a watch follows from the idea that the Moon rises at a specific time, and sets at a specific time. And when a lunar eclipse begins at a specific time and ends at another time, the Moon fits the concept of a timepiece well. On the night of March 13/14, 2025, Jean Mueller and I enjoyed a spectacular total eclipse of the Moon. In the days ahead of the event the weather forecast steadily deteriorated, and until the event was actually starting we had no idea whether we would see anything at all.
Our first check of the condition of the sky changed everything. With large breaks in the clouds we saw the Moon with a subtle darkening on its lower side. More than an hour later, the dark, reddish-brown central shadow of the Earth made its obvious first bite of the Moon. By the time the Moon was completely embalmed in the Earth’s central shadow, the umbra, the sky had darkened considerably and we were treated to one of Nature’s most stunning displays. As beautiful and artistic as the Moon appeared that night, the event followed the calculated times precisely.
“This is the most amazing, beautiful eclipse I have ever seen,” Jean said of her experience. It was electrifying for me too. Eclipses are not just events in the sky. They are awe-inspiring ruses of Nature. They do not just occur; they are inspiring, poetic. Eclipses prove that the sky is not just there; it happens. The shadow of the Earth darkens the entire face of the Moon pointed toward Earth. While an eclipse of the Sun is visible over a small area on Earth, the Moon’s eclipse can be seen over the entire side of the Earth that is going through night.
Jean was also moved by the idea of the Moon as a watch, that the stsrting and ending times of an eclipse can be accurately predicted. Decades ago, my Dad was also exhilarated when the solar eclipse of July 20, 1963, began, to the second, on time. Fascinated with history, he said that the ancient Greeks in Aristotle’s time calculated this time.
The always welcome eclipses will continue; another will be visible from my home, and from San Diego, on March 3, 2026. It will be a happy event to which I can really look forward. If the sky is cloudy that night, we will still detect a noticeable darkening around us. If it is clear, Nature will again demonstrate that just as planets form and stars die over billions of years, the eclipses start and end in periods of time measured by a few seconds.
Image 1 Credit: David Levy (The weather said there’d be clouds. Instead we got to see this!); Image 2 Credit: Tim Hunter (In Tucson it was going to rain. Instead we got this!)