Mercury and Crescent Moon Set
Innermost planet Mercury
and a thin crescent Moon are never found far from the Sun
in planet Earth's skies.
Taken
near dusk on April 8, this colorful evening skyscape
shows them both setting toward the western horizon just after the Sun.
The broad Tagus River and city lights of Lisbon, Portugal run through the
foreground under the serene twilight sky.
Near perigee or closest approach to Earth, the Moon's bright,
slender crescent represents about 3 percent of the
lunar disk in sunlight.
Of course as seen from the Moon, a nearly full Earth would light up the
lunar night, and that strong perigee
earthshine makes
the rest of the lunar disk visible in this scene.
Bright Mercury stays well above the western horizon at sunset
for northern skywatchers
in the
coming days.
The fleeting planet reaches maximum elongation, or angular distance
from the Sun, on April 18.
But Mercury will swing back toward the Sun and actually
cross the solar disk on May 9, the first
transit of Mercury
since November 8, 2006.