Twinkle, Twinkle, Little Planet?

Surprise! Hazy air produces an image of Venus that looks like a 5-pointed star.  Planets don't twinkle!  Note the ragged upper edge of the cresent moon.  Those are mountain and craters just visible at the penunbra.

Surprise! Hazy air produces an image of Venus that looks like a 5-pointed star. Planets don't twinkle! Note the ragged upper edge of the crescent moon. Those are mountains and craters just visible at the penumbra.

The cloudy skies in Eugene on 27 February, 2009 cleared at sunset giving me the chance to take photos of the beautiful conjunction between the crescent moon and Venus.  I discovered the delightful star-shaped Venus when I enlarged the photo.  The five-point star is an aberration caused by hazy light-polluted urban skies.  Planets do not twinkle due to reflected sunlight coming off of their surfaces, unlike stars, which generate their light.

The ragged upper curve of the crescent moon is actually the reflection of mountains and craters at the terminator of the penumbra (shadow).  Above the moon’s illuminated crescent, you can see Earth-shine of the entire lunar disk and if you look closely even some surface features.  Earth-shine is caused by artificial light from the Earth being reflected from the moon.  It is a modern phenomena that our ancestors never witnessed.   The halo beneath the crescent is caused by moonlight diffraction through the haze.  The picture was taken from my driveway with lots of neighborhood lights all around.

The camera I used, attached to a tripod, was a Kodak EasyShare Z650, set to manual mode.  f/8; Exposure time: 4 seconds; ISO=125; Temperature approximately 4 deg C; 35mm focal length=380mm.  The photo has not been digitally altered.

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