Ultra-thin Moon Dares You To Find It Tonight

A super skinny crescent moon as seen 20 minutes after sunset from the northern U.S. tonight April 29. The moon will be just 3 degrees or about a held horizontally at arm’s length above the horizon. Nearby Mercury will require binoculars if you see it all. Stellarium

Thanks to the moon’s repeating cycle, a wonderful observing challenge presents itself tonight. An ultra-thin crescent moon only hours old will squeak into view above the west-northwest horizon only minutes after sundown.

Fresh from this morning’s Antarctica eclipse, the moon will be just 18 hours old viewed from the East Coast, 19 from the Midwest, 20 from the mountain states and 21 from the Pacific Coast.

The one-day old evening crescent moon with Mercury (upper left) on Jan. 31 this year. Credit: Bob King

Others might be into extreme energy drinks, but I get jazzed up over extreme moons. My personal record is just shy of 24 hours, and it was surprisingly easy. Northern hemisphere late winter and early spring are the best times to catch a young moon at dusk because its angle to the horizon is very steep. Within a day after new moon, the crusty crescent already stands high enough above the setting sun to spot in the darkening sky.

Nothing quite compares to the delicacy of a hours-old moon. Spider webs and finely blown glass come to mind. The moon’s so thin you’d think it could break to pieces. Binoculars will show that it’s anything but smooth. Crater shadows cast across the precious sliver of moonscape give it a choppy, uneven appearance.

Here’s what you need to meet the challenge. Find a place where you can see as far down to the west-northwest horizon as possible and start watching at sunset. To maximize viewing time, click HERE to find out when the sun sets for your location.You’ll only have about 20-30 minutes before the moon drops too low to see through the haze. Bring binoculars and focus them on a very distant object – clouds are best – so the moon will be sharp when you eventually come across it.

Now sweep slowly above and left of the sun for a sign of the crescent. When you find it, lower the glass and try to see it with your eyes along. If you’re really lucky, you might even spy Mercury, now returning to the evening sky for one of its best appearances of the year. We’ll drop by the planet in a week or two. For now, the moon’s the apple of our eye.

4 Responses

  1. Sandra K.Keffer

    I saw this on my friends FB. Thank you for posting it.I read all about the 4 blood moons.Very interesting.When the 4/15/14 blood moon day.Here in Florida a beautiful rainbow circle was around the sun. Just gorgeous.Nothing in paper, i guess nobody took a picture of it. Are u able to look back in time at the sky that day,and see it too? i know NASA,Mathmatically can go back in time and know position of stars,seen that on EWTN series,regardinging the Bethahem star.

    or would you have a explaination for rainbow circle around our sun here in florida??
    you may email me ,but pls do not add me to any list.Again, thank you for opportunity to view this,Sandra

    1. astrobob

      Hi Sandra,
      The circle you saw around the moon was a halo created by ice crystals in high, thin clouds, similar to those that are often seen around the sun, too. A beautiful sight!

        1. astrobob

          Sad. I mean it’s great she noticed it, but it shows how people know so little about the natural world. The operator seemed just as clueless. Makes me scratch my head exactly why 911 needed to be called.

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