Skygazing at Predawn – April 19, 2012
This morning I took the chance to image the close pairing of Mercury and the thin waning crescent Moon.
Mercury an inner or inferior planets like Venus, always appear close to the sun in the sky due to their low elongation (angular separation from the sun as (angular separation from the sun as viewed from earth), hence it’s always interesting to spot this tiny elusive planet near other brighter objects such as the moon.
Neither Mercury or Venus ever appears very far from the sun and consequently never far above the horizon (except Venus at maximum elongation). Both can only appear in the west in the evening and in the east in the morning and only for a short amount of time.
Inferior planet elongation. Image credit: wapi.isu.edu
In the case of Mercury, take note that it will always be located in the sky no more than 28 degrees from the Sun.
After checking Stellarium, I prepared my trusty point-and-shoot camera and tripod and went outside before 4:00 AM. A view of Scorpius in the southwest greeted me as I set up.
The eastern horizon was fortunately clear that time. In just a little while, a thin golden arc of light began to appear above the horizon. I took my 2-inch Galileoscope out and pointed at the moon.
Thin crescent Moon rising at around 4 AM
It didn’t take long before the twilight began to creep out and push the darkness away. The sky turned blue and soon I noticed the earthshine, the ghostly illumination of the lunar dark side.
Mercury should be located only a few degrees away from the moon. I searched the area just below the lower limb of the moon where this planet was suppose to lie and found its faint shine.
It was barely visible in the images fo it lies above the glow of the rising Sun so I used the dodge tool in Photoshop during the post-editing to make it more visible.
After a few minutes of imaging, the light from the two objects were eventually washed out in the solar glow.