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.
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.
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.
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.
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.
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.
— Alan, April 9, 2019 / © 2019 Alan Dyer / AmazingSky.com