Have you been watching the old moon? That’s the name for a waning crescent moon, seen in the east before dawn. Each morning, the moon has been showing us less and less of its lighted side. It’s been rising closer to the sunrise. It’s heading toward new moon on March 17.
This month’s waning moon swept past the planets Jupiter, Mars and Saturn before dawn. See photos here.
If you do see the moon between now and March 17, it’ll appear as a very thin crescent that’ll rise in the east shortly before the sun. By Friday morning, March 16, the moon will become difficult to see before dawn from Earth’s Northern Hemisphere. But this is a wonderful time of year to look for a very old moon – a very slim waning crescent that’s near the sunrise – as dawn is breaking across Earth’s Southern Hemisphere. The reason is that the ecliptic – marking the approximate path of the sun, moon and planets across our sky – makes a narrow angle with the sunrise horizon now, as seen from northerly latitudes. Meanwhile, from southerly latitudes on Earth, the ecliptic stands nearly straight up with respect to the sunrise horizon, so the moon is above the sunrise and easier to see.
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
Bottom line: The moon is now in a waning crescent phase. New moon will come on March 17, 2018.
Deborah Byrd created the EarthSky radio series in 1991 and founded 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.