M11 is best viewed in the hours between sunset and midnight in August, when the cluster can be found roughly 40 degrees above the southern horizon. Remember, the width of your clenched fist held at arms length is the equivalent of 10 degrees in the night sky.

Here's what to know. When the moon is nearly between Earth and the sun, one side of the moon faces the sun, and that side is illuminated, but the side the Earth sees is dark. This is called the new moon phase of the lunar cycle — when the moon isn't visible at night.

This week, the cosmos is serving up a celestial twist: a rare “black moon” on August 23 — an event so mysterious that the moon itself disappears completely from view, even as it captures the world’s imagination.