A rare ‘black moon’ rises Friday night over the Western Hemisphere, but don't expect to see it.
NASA says a black moon is the second new moon in a calendar month. A new moon is the start of the lunar cycle and the phase where the moon is impossible to see because it's completely shrouded in darkness.
A black moon occurs about once every 32 months. Friday night's officially takes place at 8:11pm on the east coast.
The term ‘black moon’ contrasts with ‘blue moon’, which is the second full moon in a calendar month.
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