April 9, 2019 – The Amazing Sky

Spring is the season for Earthshine on the waxing Moon.

April 8 was the perfect night for capturing the waxing crescent Moon illuminated both by the Sun and by the Earth.

The phase was a 4-day-old Moon, old enough to be high in the sky, but young enough – i.e. a thin enough crescent – that its bright side didn’t wash out the dark side!

In the lead photo at top, and even in the single-exposure image below taken earlier in a brighter sky, you can see the night side of the Moon faintly glowing a deep blue, and brighter than the background twilight sky.

Four-Day-Old Moon in Blue Twilight — The 4-day-old waxing crescent Moon on April 8, 2019 in a single exposure when the Moon was still in the bright blue twilight. Even so, the faint Earthshine is just becoming visible. This is with the 105mm Traveler refractor and 2X AP Barlow lens for an effective focal length of 1200mm at f/12, and with the cropped-frame Canon 60Da at ISO 400, in a single 1/8-second exposure.

This, too, is from sunlight, but light that has bounced off the Earth first to then light up the night side of the Moon.

If you were standing on the lunar surface on the night side, the Sun would be below the horizon but your sky would contain a brilliant blue and almost Full Earth lighting your night, much as the Moon lights our Earthly nights. However, Earth is some 80 times brighter in the Moon’s sky than even the Full Moon is in our sky.

Four-Day-Old Moon with Earthshine — The 4-day-old waxing crescent Moon on April 8, 2019 in a blend of short and long exposures to bring out the faint Earthshine on the dark side of the Moon and deep blue twilight sky while retaining details in the bright sunlit crescent. This is with the 105mm Traveler refractor and 2X AP Barlow lens for an effective focal length of 1200mm at f/12, and with the cropped-frame Canon 60Da at ISO 400, in a blend of 7 exposures from 1/30 second to 2 seconds, blended with luminosity masks from ADP Pro3 extension panel in Photoshop.

Unlike the single image, the lead image, repeated just above, is a multi-exposure blend (using luminosity masks), to bring out the faint Earthshine and deep blue sky, while retaining details in the bright crescent.

Once the sky gets dark enough to see Earthshine well, no single exposure can record the full range in brightness on both the day and night sides of the Moon.

Waxing Moon, Mars and the Taurus Clusters — The 4-day-old waxing crescent Moon on April 8, 2019 with it below Mars (at top) and the star clusters, the Hyades (at left, with reddish Aldebaran) and Pleiades (at right) in Taurus, and set into the deep blue evening twilight. This is with the 135mm Canon telephoto at f/2.8 with the Canon 6D at ISO 400, in a blend of 7 exposures from 1/4 second to 8 seconds, blended with luminosity masks from ADP Pro3 extension panel in Photoshop, to prevent the Moon from being too overexposed while retaining the stars and blue sky. The camera was tracking the sky.

April 8 was a great night for lunar fans as the crescent Moon also appeared between the two bright star clusters in Taurus, the Hyades and Pleiades, and below reddish Mars.

It was a fine gathering of celestial sights, captured above with a telephoto lens.

April 8 Sky

This show the chart I used to plan the framing, created with StarryNight™ software and showing the field of the 135mm lens I used.

The chart also shows why spring is best for the waxing Moon. It is at this time of year that the ecliptic – the green line – swings highest into the evening sky, taking the Moon with it, placing it high in the west above obscuring haze.

That makes it easier to see and shoot the subtle Earthshine. And to see sharp details on the Moon.

$The 4-day-old waxing crescent Moon on April 8, 2019 exposed for just the bright sunlit crescent, revealing details along the terminator. This is with the 105mm Traveler refractor and 2X AP Barlow lens for an effective focal length of 1200mm at f/12, and with the cropped-frame Canon 60Da at ISO 400, for a single exposure of 1/60 second. This is not a stack or mosaic.$

The 4-day-old waxing crescent Moon on April 8, 2019 exposed for just the bright sunlit crescent, revealing details along the terminator. This is with the 105mm Traveler refractor and 2X AP Barlow lens for an effective focal length of 1200mm at f/12, and with the cropped-frame Canon 60Da at ISO 400, for a single exposure of 1/60 second. This is not a stack or mosaic.

After the sky got darker I shot the crescent Moon in a short exposure to capture just the bright crescent, included above in two versions – plain and with labels attached marking the major features visible on a 4-day Moon.

If you missed “Earthshine night” this month, mark May 7 and 8 on your calendar for next month’s opportunities.

Clear skies!