Hey! What’s that? Paula Graham took an astronomically intriguing photograph from outside of her house (Devon in UK). But something doesn’t look quite right…the full moon appears to be cuddling with a lunar crescent: what kind of cosmic sorcery is this?!?! A waxing crescent moon can never align opposite the sun in the sky—so it’s not possible to see the moon’s disk…or is it?
Question: What is Earthshine?
Answer: Sunlight reflects off Earth’s surface, and then illuminates the moon’s night side (kind of like a planetary flashlight).
Earthshine is best seen during a waxing or waning lunar crescent phase, however, atmospheric conditions determines the clarity and visibility of earthshine, so it’s not possible to accurately predict when earthshine will be visible. Sorry. Pollution, clouds, haze, smog, fog—all of those lovely things obscure earthshine’s delicate glow.
** How to See Earthshine **
Observe every waxing or waning crescent moon
Seek a location far away from highly populated cities
Listen to the sky! If atmospheric conditions feel right—go outside and confirm your suspicions
Thunderstorms are known to scrub away atmospheric pollutants. Try locating a crescent moon after a thunderstorm and you may see earthshine.
A crescent moon may hang low on the horizon! Trees (and other environmental objects) could obscure your view
Thanks for sending me the photo, Paula!
Paula’s image specifications:
Camera: Nikon D3
Lens: Nikkor 70-200mm
Exposure: 1/5 second (Handheld)
Processing: RAW file (Adobe Photoshop 6)
** Earthshine Photo-Gallery **