Birkat Halevana – Blessing the moon (Hebrew: ברכת הלבנה ) is not a black magic. It is actually one of the three essence of Judaism.
Upon seeing the moon at the beginning of the month one says a blessing called Birkat HaLevana (for the details and text see below). What’s the significance of this Bracha? The Gemara Sanhedrin 42a says that saying Birkat HaLavana is like greeting the Shechina. Beiur Halacha 426:2 explains that by seeing the moon fulfill its mission consistently we recognize Hashem’s might and control over nature. He adds that to emphasize that we only pray to Hashem and the moon is just a tool by which we can recognize Hashem’s strength we say Aleinu afterwards. (See note for more about the significance of this Bracha.
The Laws and the Blessing
I was surprised to find a dedicated website just for the blessing of the moon, it is here >>