Your Earth Sky News for March 3rd: First quarter moon comes March 5

First quarter moon comes March 5

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A first quarter moon is a waxing moon, rising at noon, highest at sunset. This month’s full moon comes on March 12.

A first quarter moon shows half of its lighted hemisphere – half of its day side – to Earth.

First quarter is March 5, 2017 at 11:32 UTC. It’s a waxing moon, in the sky each evening when the sun goes down. Next full moon is March 12.

We call this moon a quarter and not a half because it is one quarter of the way around in its orbit of Earth, as measured from one new moon to the next.

Also, although the moon appears half-lit to us, it’s good to recall that the illuminated portion of a first quarter moon truly is just a quarter. On the night of first quarter moon, we see half the moon’s day side, or a true quarter of the moon. Another lighted quarter of the moon shines just as brightly in the direction opposite Earth!

And what about the term half moon? That’s a beloved term, but not an official one.

A first quarter moon rises at noon and is highest in the sky at sunset. It sets around midnight. First quarter moon comes a week after new moon. Now, as seen from above, the moon in its orbit around Earth is at right angles to a line between the Earth and sun.

 

 

Deborah Byrd

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.

Published on EarthSky