Physics Photo of the Week
February
16, 2007
Mercury and Venus
The planet
Mercury has been visible the past 1-1/2 weeks very low in the western
sky soon after sunset. Mercury is the red object just at the tips
of the trees at the horizon. Venus is the much brighter object at
upper left. The small speck to the right of Venus is an artifact
- presumably internal reflections on the camera lens.
If the weather is clear you may see Mercury - the closest planet to the
Sun - but you need to look no later than 7:00 pm. You need a
clear view of the western horizon - unobstructed by mountains and
trees. Mercury is also very red as the photograph indicates, and
is actually quite bright. It is not as bright as Venus, but it is
brighter than many "bright" stars.
The photograph was taken on February 10, 2007 at about 
7:00 pm.
12 exposures were made lasting about 5 seconds each. The images
were then co-added - lining up the planets in each
image. Because
celestial objects appear to move across the sky, the trees appear
streaked in the co-added images. Otherwise the celestial objects
would appear streaked. The image at the right shows a straight
sum with no alignment. The planets (and stars if visible) appear
streaked due to the apparent movement of the sky.
If you miss seeing Mercury during this apparation, it will soon be
visible in the east morning before sunrise in early March, but it will
be much lower in the sky. The next
evening appearance of Mercury will be late May - early June,
2007. Mercury appears frequently, but remains visible only for
short durations due to its short orbital period about the Sun (88
days). Venus will be
highly visible all through the spring of 2007 and reach it's peak
brightness in late June, 2007 just after Mercury rejoins Venus in the
evening sky. Enjoy the skies!
Physics
Photo of the
Week is
published weekly during the academic year on Fridays by the Warren
Wilson College Physics
Department. These photos feature an interesting phenomena in
the world around us. Students, faculty, and others are invited to
submit digital (or film) photographs for publication and
explanation. Atmospheric phenomena are especially welcome.
Please send any photos to dcollins@warren-wilson.edu.
Click
here to see the Physics Photo
of
the Week Archive.
Observers are invited to submit
digital photos to:
