Thierry Legault Photographs World Record Youngest Possible New Moon

Thierry Legault’s world record thinnest moon photographed in full daylight through a 4-inch refracting telescope on July 8. Copyright: Thierry Legault

You’ve probably remarked at the beauty of a thin crescent moon sometime in your life, but for really really thin you can’t do better than a photograph of the new moon itself. French astrophotographer Thierry Legault achieved this seemingly impossible feat on July 8 when the moon was exactly at new phase and closely lined up with the sun.

Thierry Legault’s setup for taking the “thinnest” crescent picture. Credit: Thierry Legault

Because sun and moon were separated by only 4 degrees (less than the spacing between the two stars at the end of the Big Dipper’s bucket), Legault had to shoot his photo through a custom shade – with a hole punched out for the moon – to block the solar glare and reduce skylight.

To further increase the moon’s contrast against the blue sky he used a camera sensor sensitive to near-infrared light, a “color” of light just long of the red end of the rainbow spectrum.

You gotta love it when someone takes a new approach to doing something most thought impossible … and it works splendidly.

Just look at that cat-scratch crescent. You’ll probably never see one thinner.  Well, I shouldn’t say never. During a total solar eclipse, the moon passes directly in front of the sun and the percentage of visible crescent drops to zero. Such perfect alignments only happen a few times a year for specific locations on the planet. The moon’s slightly tilted orbit around the Earth normally means it’s a bit north or south of the sun at the moment of New Moon, leaving a razor-thin crescent in view. No one sees this crescent because it’s much too close to the sun and lost in glare.

The youngest moon I’ve ever seen was just shy of 24 hours. Positively ancient compared to Legault’s zero-hour-old crescent. Notice too that the crescent is unevenly illuminated. That’s because the moon’s surface is rough and cratered. Low spots don’t get as much sunlight as high spots like crater walls, breaking the moon’s delicate form into lighter and darker segments.

Watch for the crescent moon and Venus tonight at dusk. The map shows the sky facing west-northwest about a half hour after sunset. Maps created with Stellarium

Ordinary humans like you and I can spy the lunar crescent tonight shortly after sunset. Faithful to its orbital rhythm, the moon has returned to grace evening twilight and will appear near the bright planet Venus. Watch as the two glide in tandem toward the western horizon.

4 Responses

  1. Edward M. Boll

    Great planet show in the morning with Jupiter, Mars and Mercury with the Perseids flaring about the time that Mercury once again disappears. 2 months till we have a Venus Saturn conjunction, culminating past mid September.. Hopefully ISON will be visible in large binoculars then. It will be a low morning object. Looking at the prospects and ISON’ s placing in the sky from mid December through early January, things could hardly get better.

  2. Well described except for the statement “Technically the moon isn’t precisely new. If it were, it would sit directly in front of the sun creating a total eclipse.” The moon is precisely new at a certain instant in every lunation (cycle around the sky), whether it is exactly in front of the sun or not.

    1. astrobob

      Hi Guy,
      Thank you for writing. By the way, I’ve been a fan of your books for many years. Well, I’ve learned something new then (excuse the pun). I always considered any remaining crescent, no matter how thin, to be a departure from a true New Moon. Since the definition is “conjunction with the sun” you’re absolutely correct. Thank you very much for the clarification.

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