See the Youngest Moon of Your Life Tonight

by Bob King on January 1, 2014

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A 24-hour-old moon photographed from Duluth, Minn. U.S. on in May 2010. Credit: Bob King

A 24-hour-old moon photographed from Duluth, Minn. U.S. on in May 2010. Credit: Bob King

The new year starts out with a bang, offering the chance to spy an exceptionally thin crescent moon shortly after sunset. Here’s how to find it. 

The moon’s age is determined by how many hours or days have passed since new moon phase. New moon occurs once a month when the moon lies in nearly the same direction as the sun in the sky. No one can see a new moon because it stays very close to the sun and lost in the glare of daylight.

To attempt your personal youngest moon yet, find a flat horizon to the southwest and start looking about 10 minutes after sunset. This panel shows the sky from four different locations. The times shown are 20 minute after local sunset and the moon's elevation at those times is also noted. Created with Stellarium

To attempt your personal youngest moon yet, find a flat horizon to the southwest and start looking about 10 minutes after sunset. This panel shows the sky from four different locations. The times and moon’s elevation are shown for 20 minutes after local sunset. The moon’s orientation is approximate. Created with Stellarium

Under favorable circumstances it isn’t too difficult to spot a 1-day-old moon, referred to as a young moon because it’s the first or youngest bit of moon we see after new moon. Young moons are delicate and tucked far down in the twilight glow shortly after sunset. Spotting one fewer than 24 hours old requires planning. You need a flat horizon, haze-free skies and a pair of binoculars. Being on time’s important, too. Be sure to arrive at your observing spot shortly before sundown. Knowing the point on the horizon where the sun sets will guide you to the crescent’s location.

An 18-hour-old crescent moon photographed in a 12-inch telescope on April 22, 2012. Credit and copyright: John Chumack and Maurice Massey

An 18-hour-old crescent moon photographed in a 12-inch telescope on April 22, 2012. Credit and copyright: John Chumack and Maurice Massey

Ready to rock and roll? New moon occurred at 5:14 a.m. (CST) today. For the U.S. Midwest that makes the moon approximately 12 hours old at sunset this evening. Since the moon moves to the east or away from the sun at the rate of one moon-diameter per hour, skywatchers in the western U.S. will have it somewhat easier shot at seeing it. In Denver, the moon will be 13 hours old, while in San Francisco it will have aged to 14 hours. Hawaii residents will have their shot at a 16-hour-old moon, still very young but farther yet from the sun and easier to see. To know exactly when the sun and moon set for your city, click HERE.

Luckily you’ll have more than just the sunset point to help know in which direction to look; Venus, itself a very thin crescent moon at the moment, hovers 7-8 degrees to the upper left of the moon. You should have no problem seeing a crescent Venus in binoculars.

The record for youngest moon spotted with the naked eye goes to writer and amateur astronomer Steven James O’Meara, who nabbed a 15 hour 32 minute crescent in May 1990. The skinniest moon ever seen with optical aid goes to Mohsen G. Mirsaeed of Tehran on September 7, 2002 at just 11 hours 40 minutes past new.

Venus, seen here several years back to the lower right of the moon along with Jupiter, will not only help with focus tonight but will guide toward the thin crescent. Credit: Bob King

Venus, seen here several years back to the lower right of the moon along with Jupiter, will not only help with focusing tonight but will guide skywatchers toward the thin crescent. Credit: Bob King

Based on these facts, it’s likely few will see the faint arc of moon with the naked eye especially in the eastern U.S. where the crescent will be only 11 hours old. Binoculars and telescopes will be required for most of us.  To meet tonight’s challenge, make sure your binoculars are focused at infinity before you start. Again, Venus comes to our aid. Carefully focus the planet until you see its crescent as sharply as possible. You can also focus on any clouds that might be present. Lacking that, aim for the most distant object in the landscape. Focus is critical. If you’re off, the thin moon will soften, spread out and appear even fainter.

I couldn't resist adding this pic of the waning moon taken by one of the International Space Station astronauts as it rose over the limb of the Earth. Credit: NASA

I couldn’t resist adding this fine photo of the waning moon taken by one of the International Space Station astronauts as it rose over the limb of the Earth. Credit: NASA

Start looking for the moon about 10 minutes after sundown in nearly the same direction as the sunset point within a strip of sky as wide as a typical binocular field of view or about 5 degrees. Slowly scan up and down and back and forth over the next 25 minutes looking for a wispy sliver of light against the deepening blue sky. Should you find the moon, you might be surprised at the broken appearance of the arc. These seeming breaks are caused by oblique lighting on crater walls and mountain peaks creating shadows long enough to bite into and hide portions of the moon’s sunlit edge.

I wish you the best in your search tonight for what could be one of the rarest astronomical sightings of your life. It won’t be easy. Whether you succeed or not, please drop us a comment and share your story.

About 

I'm a long-time amateur astronomer and member of the American Association of Variable Star Observers (AAVSO). My observing passions include everything from auroras to Z Cam stars. Every day the universe offers up something both beautiful and thought-provoking. I also write a daily astronomy blog called Astro Bob.

thomas C January 1, 2014 at 5:18 PM

you actually can see a new moon in daylight in the Earths reflection when the conditions are

Sean Cassidy January 3, 2014 at 10:43 AM

umm, really? care to elaborate?

Rick Blount January 1, 2014 at 8:56 PM

I am increasingly frustrated by headlines like this on websites that are for the global community. I and many other readers(not in America) will not see the new moon on this day.Therefore the headline is inaccurate.

Other_events January 2, 2014 at 1:52 AM

Absolutely correct. Eloquently and accurately stated…regards from the southern (and eastern) hemisphere.

Tony Trenton January 2, 2014 at 6:52 AM

Use your common sense.
Get over it

Other_events January 2, 2014 at 9:04 AM

Certainly…with many thanks for your understanding.

Sean Cassidy January 3, 2014 at 10:49 AM

while this is a global site, i’m sure a disproportionate percentage of users are from N America, 1st off. Second, even here in N America the East Coast where i live had almost no chance of seeing it. but why should i be annoyed at the post because of that? Should only events that are visible worldwide be included on this site? if that’s the case almost nothing would be included. also, as i read it the headline refers to the possibility of seeing it. not a guarantee. plenty of people in the geaographically possible zone wouldn’t have been able to see it due to cloud cover etc. should they sue universe today over the headline?

Rob Sparks January 2, 2014 at 11:33 AM

I got it from Arizona at 14 hours 46 minutes past new. http://www.flickr.com/photos/halfastro/sets/72157639298787074/

Sean Cassidy January 3, 2014 at 10:44 AM

that is AWESOME!!!! having even spotted it. great shots too! did u use optical aid to find it?

Rob Sparks January 3, 2014 at 10:57 AM

I didn’t see it naked eye. I was using 8×42 binoculars. The west was slightly hazy…might have gotten it naked eye if that haze wasn’t there.

Sean Cassidy January 5, 2014 at 4:48 AM

well that is great either way. my personal record smallest crescent was 31 hours and 32 minutes prior to new moon, so u have me beat by a bunch! tho that was a naked-eye sighting, so not 100% comparable.

Bill January 2, 2014 at 8:17 PM

I saw it 5:15 – around 5:25pm, Niceville Florida. Thanks

Sean Cassidy January 3, 2014 at 10:42 AM

u mean yesterday not Wednesday right?

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