of the Week
October 28, 2005
Here Comes Mars!
approaching its closest approach to the earth for the current observing
season. (Conversely, earth is making its closest approach to
Mars). To view Mars this week, you need to look in the Eastern
sky soon after 11:00 pm - the approximate time when Mars rises.
Alternatively, you can look high overhead at about 6:30 am - excellent
for those who get up early. The earth will be at the closest
approach to Mars in late October at about 43 million miles. The
two planets were closer in late August, 2003 at 35 million miles.
The photo above was taken at about 5:30 am on Sept. 15, 2005 with a
digital camera aimed at the Mars' region of the sky using a
tripod. To increase the visibility of stars, a series of 15
second exposures was taken. 16 of these time exposures were
aligned and "stacked" using special software to compose a relatively
clear image. The contrast and colors were also enhanced to bring
out the colors.
Mars near the center in this sky photo, the familiar Pleiades star
cluster (often referred as "the Seven Sisters") is seen at top center,
Aldebaran (alpha Tauri) and the Hyades "V-shaped" cluster in the upper
left, and the 2 stars of Aries on the extreme right. This same
part of the sky was visited by Comet Macholz last winter (See
PPOW for January 10, 2005) and reproduced at left. Also
notice in the top photo the bluish color of the Pleiades compared to
red color of Mars and Aldebaran, and the "medium" color of the stars in
Aries on the right.
Mars will move in the sky throughout the fall and winter of
2005-06. We (students, colleagues, and myself) will be taking
photos of Mars in the sky to examine how Mars moves relative to the
background of stars. Here is a "quiz": Both Mars and earth
are moving around the sun, so the perspective position of Mars will
change as the seasons progress. Both planets (as well as the
other 7 main planets of the Solar System) orbit the sun towards the
east. How is Mars going to appear in successive
photographs? Will it travel further east to join Taurus and
Aldebaran, or will it move further west towards the constellation
Aries? The answer will not be published until December when more
photographs have been made and stacked.
Physics Photo of the
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 firstname.lastname@example.org.
here to see all Physics Photo of the Week for 2005
to see all Physics Photo of the Week for 2004.