A waning crescent moon is sometimes called an old moon. It’s seen in the east before dawn. This month’s old moon swept past the brightest planet, Venus, in a spectacular display on Monday morning, May 22 (see photos). The following morning – Tuesday, May 23 – the moon will be near Mercury.
At this moon phase, the moon has moved nearly entirely around in its orbit of Earth, as measured from one new moon to the next. New moon will come on May 25, 2017 at 19:44 UTC; translate to your time zone. The May 25 new moon will be the closest supermoon in 2017.
Because the moon is nearly on a line with the Earth and sun again, the day hemisphere of the moon is facing mostly away from us once more. Over the past several mornings, we’ve been seeing only a slender fraction of the moon’s day side: a crescent moon. Because the moon moves eastward in orbit around Earth, the moon has been appearing closer to the sunrise glare.
Watch for it Monday and Tuesday mornings, near the planets.
Will you see the moon on Wednesday? It would be very, very difficult since the moon will be so close to the sunrise. Still, the waning crescent will be up there on Monday, Tuesday and Wednesday – nearly all day long – moving ahead of the sun across the sky’s dome.
The old moon sets in the west shortly before sunset.
As the moon orbits Earth, it changes phase in an orderly way. Follow these links to understand the various phases of the moon.
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
Deborah Byrd created the EarthSky radio series in 1991 and EarthSky.org in 1994. Today, she serves as Editor-in-Chief of this website. She has won a galaxy of awards from the broadcasting and science communities, including having an asteroid named 3505 Byrd in her honor. A science communicator and educator since 1976, Byrd believes in science as a force for good in the world and a vital tool for the 21st century. "Being an EarthSky editor is like hosting a big global party for cool nature-lovers," she says.