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Where’s the moon? Waning crescent

When is the last waning moon you’ll see before Monday’s eclipse? If you’re in the Northern Hemisphere – and have a clear sky – probably Sunday morning. Look east before sunup.

Karl Diefenderfer of Quakertown, Pennsylvania caught the moon on the morning of August 16, 2017, near the bright star Aldebaran in the constellation Taurus the Bull. Karl wrote: “I’m very excited to see the moon age because that means the solar eclipse is almost upon us!”

A waning crescent moon is sometimes called an old moon. It’s seen in the east before dawn. This month’s old moon recently swept past the star Aldebaran. It’s due to pass near Venus on the mornings of August 18 and 19. The moon is now showing us less and less of its lighted side each morning, and rising closer to the sunrise. It’s heading toward new moon and a rendezvous with the sun – a total solar eclipse – on August 21, 2017!

Enter your zip code to learn how much eclipse you’ll see, and what time

Moon waning and moving toward the sun, in the days before the eclipse. The moon’s motion is a reflection of its orbital path around Earth. Image via Guy Ottewell. Used with permission. See the planets near the eclipsed sun on this chart? Read more: See 4 planets at totality.

Over the next several mornings, watch for the waning crescent moon in the early morning sky. You’ll see it get slimmer and slimmer as it heads toward the eclipse. When’s the last waning moon you’ll see before eclipse day? From the Northern Hemisphere, it should be fairly easy to pick out the very slim waning crescent, very close to the sunrise point on the horizon, just before sunrise on Sunday, August 20.

As the moon orbits Earth, it changes phase in an orderly way. Follow these links to understand the various phases of the moon.

Four keys to understanding moon phases

Where’s the moon? Waxing crescent
Where’s the moon? First quarter
Where’s the moon? Waxing gibbous
What’s special about a full moon?
Where’s the moon? Waning gibbous
Where’s the moon? Last quarter
Where’s the moon? Waning crescent
Where’s the moon? New phase

Moon in 2017: Phases, cycles, eclipses, supermoons and more

Deborah Byrd