There are few sights in nature as delicate and beautiful as the crescent moon. This week, that crescent moon will dominate the sky after sunset.
Starting this Wednesday and continuing into the weekend, the moon will change from a thin crescent to a thicker, brighter crescent. And perhaps the most captivating sight of the week is “Da Vinci’s Radiance.”
What is “da Vinci’s brilliance”?
The faint light seen on the non-lit side of the crescent moon is called the “Da Vinci glow.” It is named after the Italian astronomer Leonardo da Vinci, who first observed it.
Da Vinci’s brilliance is generally referred to as the “Earthshine.” That’s because the Earth is causing this phenomenon, not the moon. Earthshine is a phenomenon in which sunlight reflecting off the Earth’s clouds and ice illuminates the moon, creating a faint glow.
It is only visible when the moon is a narrow crescent, and it will be visible every night this week. NASA explains that Earthshine brightness varies throughout the year due to changing cloud and ice conditions.
Where and when to see “Da Vinci’s Radiance”
Since Monday, November 13th was a new moon, on Tuesday the 14th, an extremely thin crescent moon with a luminous area ratio of only 4% appeared in the southwest sky just after sunset, just above the horizon, but it was difficult to see with the naked eye. was.
Below are the timings when you should actually see the crescent moon and the “da Vinci’s brilliance,” or Earthshine. It appears a little higher in the sky after sunset, making it much easier to see.
・Thursday, November 16th: A rising crescent moon with a bright surface ratio of 10% (twilight sky)
・Friday, November 17th: Waning crescent moon with brightness ratio of 18% and Earthshine (with the stars of Sagittarius in the twilight sky)
・Saturday, November 18th: The rising crescent moon with a brightness ratio of 27% and the Earthshine (with the stars of Sagittarius in the twilight sky)
The best time to see the Earthshine is about 30 minutes after sunset on Friday the 17th. Theoretically, earthshine always exists, but once the moon’s bright surface ratio exceeds 25%, the faint earthshine is overwhelmed by the bright moonlight, making it difficult to see. It’s becoming.
How to watch “Da Vinci’s Radiance”
“Da Vinci’s Radiance” can be seen with the naked eye, but if you have binoculars, it’s worth a peek. You’ll see shadows cast in craters and mountains near the border between the bright and dark parts of the moon.
And if you point your binoculars at the moon’s dark edge, you can see the moon’s surface, 380,000 km away, revealed by light coming from Earth’s ice caps and clouds.
