At this time of year where we live, it's dark by the time the students and I pour forth from the synagogue at the end of Monday afternoon Hebrew school. And now that my son is in kindergarten, he comes to Monday Hebrew school just as the older kids do. So the two of us walk out of the shul together into the afternoon dark.

Last night as we approached the car, he looked up at the sky and crowed, "I see the moon!" And then, a moment later, he added -- with wonderment -- "it's a crescent, but I can see the rest of it, look, it's dark grey!" I told him that this is a waxing crescent moon; we are four days into the lunar month of Kislev, so the moon is growing bigger.

The waxing crescent moon is beautiful, of course... and so is the more muted light which my son admired on the remainder of the satellite, the dim but perceptible silhouette of the rest of the moon. That pale glow, it turns out, is earthshine -- light reflected from the earth onto the moon. When the moon is a crescent, if we could stand on its surface we would see a full earth hanging in space. Earthshine is the glow from the full earth, reflected back onto the night side of the moon.

Earthshine isn't visible all night long -- only for a short while after sunset, and a short while before sunrise. But if you catch the crescent moon at those liminal times, you can glimpse the rest of the moon, too. That the moon illuminates the earth is no surprise to me. The full moon is a thing of beauty, and shines so brightly! But that our earth illumines the moon in turn -- I never knew that. I'd seen it before, but didn't know what it was.

In Jewish tradition the moon can represent Shekhinah, divine Presence: sometimes hidden and sometimes revealed, but always with us. If the moon represents divine Presence, then maybe earthshine represents how our yearning for God makes God more present, more "visible," to us. As we gaze upward and yearn for the One, the light of our souls shines forth -- and even though our individual lights are tiny, collectively we shine enough light to illuminate God from afar.

As earthshine illuminates the moon which in turn beams more light upon us, so our souls -- thirsty for connection -- shed light on God Who pours light down on us in turn. Earthshine only manifests when the moon isn't full -- or in Jewish mystical language, it's precisely when God seems most hidden that we are called to yearn and to seek. (The Zohar has a phrase for this: אתערותא דלתתא, "arousal from below." Sometimes connection between us and God comes from "on high;" other times it's sparked by our yearning "from below.")

There are times when God's light is brilliant -- full moon, as it were. And there are times when God's light is scant... and it's precisely at those times when our yearning can most fully call divine light forth, just as earthshine is only possible when the moon is mostly hidden from view. God's hiddenness is an invitation to us to seek and to yearn. And the very act of our seeking makes God more findable -- just as the light of our faraway planet helps the moon herself to shine.