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THE INTERNATIONAL MARSWATCH ELECTRONIC NEWSLETTER
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Volume 3; Issue 4
April 27, 1998
Circulation: 1447
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Dear Marswatch participant,
Mars Global Surveyor continues to return spectacular images and
other data during its orbit-lowering maneuvers. Initial scientific
results were reported in the March 13, 1998 issue of Science
magazine, and an array of spectacular new images (including pictures
from the south pole, Cydonia, and Viking Lander regions) and other
data can be found on the JPL Mars Global Surveyor WWW site, or at
the home page for the Mars Orbital Camera investigation. The URLs
for both are:
http://mars.jpl.nasa.gov/mgs/index.html
http://www.msss.com
A new site where a large number of educational and other Mars resources
have been compiled can be found at
http://marswatch.tn.cornell.edu/marsidea.
The "Educational Tools" link should be particularly interesting for K-12
teachers and other educators interested in hand-on classroom activities
related to Mars and Planetary Science.
While our favorite planet is far on the other side of the solar system,
now is the time to start planning for the next round of telescopic
observations. To get you started, here is the first of a four-part series
of Marswatch emails dedicated to preparations for the 1998-1999
observing season. The series was written by Jeff Beish and other
experienced Mars-observing colleagues who are involved with the
Association of Lunar and Planetary Observers. Enjoy!
--Jim Bell
Cornell University
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1998-1999 APHELIC APPARITION OF MARS: PART 1
By: Jeffrey D. Beish
With Donald C. Parker, M.D., Daniel Troiani, and Daniel Joyce
INTRODUCTION
Recent Spacecraft missions into our Solar System have
sparked renewed public interest in planetary sciences. The Mars
Global Surveyor space mission will bring the first close-up
surveillance of the Red Planet Mars since the Viking I and II visits
during the mid-1970's and early 1980's.
While the past accomplishments of U.S. space missions
throughout the Solar System has yielded extensive volumes of
scientific information we never the less ponder many questions about
the Earth-like planet Mars.
Some of those questions remain unanswered today: Are the
polar climates static or are they changing over long periods of time?
Can surface wind directions be inferred from cloud formations and
movements? Are equatorial water ice crystal clouds seasonal? If so,
can their appearance and locations be predicted? What causes the
secular (long-term) changes in dark albedo features? Are their
locations topographically controlled or result from unseasonable
winds? These are just a few of the important questions remaining in
the Martian mystery.
Still an intriguing world, Mars offers the casual and serious
observer both alike many challenges and delights. This planet offers
astronomers a free laboratory for the study another planet's
atmosphere: the behavior of condensates and effects on its
atmosphere. Mars is similar to Earth in that it has four seasons,
exhibits global climates, changing weather patterns, annual thawing of
polar caps, storm clouds of water ice, howling dusty winds, and a
variety of surface features which predictably change with color and
size and move around the surface over long periods of time.
THE A.L.P.O. AND THE I.M.P.
The International Mars Patrol (I.M.P.) is an international
cooperative effort between individual observers and members of
observing groups located around the world. Established in the late
1960's by the late Charles F. Capen, the IMP has contributed more
than 30,000 observations of Mars. Contained within the archives of
the Association of Lunar and Planetary Observers (A.L.P.O.) Mars
Section library are the records of fifteen apparitions of Mars covering
a span of 35 years.
From the late 1960's, interested amateur and professional
astronomers located in 47 foreign countries and U.S. territories
cooperated in a 24-hour watch on the Red Planet Mars. Additional
support is provided by the British Astronomical Association
(B.A.A.), the Arbeitskreis Planetenbachter (Germany), and JapanŐs
Oriental Astronomical Association (O.A.A.).
THE A.L.P.O./I.M.P. OBSERVING PROGRAM FOR
MARS
The I.M.P. coordinates and instructs the cooperating
observers in using similar visual, photographic, photometric, and
micrometric techniques employing color filters and standard methods
for reporting their observations, which results in homogeneous sets of
observing data that have good analytic value.
Each apparition the A.L.P.O. Mars Section receives thousands
of individual observations consisting of visual disk drawings made
with the aid of color filters, black-&-white and color photographs,
intensity estimates of light and dark albedo features, color contrast
estimates, and micrometer measurements of polar caps, cloud
boundaries, and variable surface features during the 10 to 12 month
observing period. The chronological filing of this large quantity of
data requires the observation information obtained for each night
Universal Date be recorded on one or two standard observing report forms!
It is with this regard that the A.L.P.O. Mars Coordinators have
prepared a simple, efficient and standard Mars observing Report
Form. This Standard Form, or its format, can be used for reporting all
types of observations such as; micrometry, transit timings, intensity
estimates, etc. Photographs may also be attached to the top or back of
the form and the relevant information blanks to be filled in at the
telescope. Planetary aspects blanks can be filled in at other times than
while observing [Capen et al, 1981].
Observational data consist of color filter photography, visual
disk drawings, visual photometry (intensity estimates on the standard
ALPO scale: 10 = polar brightness, 8 = desert mean brightness, 0 =
night sky), micrometry, and CCD imaging. Great emphasis is placed
on quality photographs in red, blue, and violet light, full disk
drawings using standard color filters, polar cap measurements made
with the astronomical micrometer, and with modern observing
techniques such as full disk photometry and CCD imaging.
It is highly recommended that all observers, visual as well as
photographers and CCD camera users, use at least a basic set of
tricolor filters according to the following guide: Red or Orange (W-25
or W-23A); Green (W58); Blue-Green (W-64); Blue (W-38A or W-
80A); and Violet (W-47). Observers with smaller telescopes, such as
3 to 6-inch apertures may find a Yellow (W-15) useful and may
provide better performance than the deep red filter (See Table 1).
Those employing larger instruments, such as 8 to 16-inch apertures,
will find the deep Red and Blue filters most useful for fine surface
details or atmospheric cloud detection [Capen, et al, 1984].
Table 1. Eastman Kodak Wratten Filters used by A.L.P.O. observers.
Characteristics for Mars Observations.
Yellow (W12, W15) to brighten desert regions, darkens bluish
and brownish features.
Orange (W21, W23A) further increases contrast between light and
dark features, penetrates hazes and most clouds, and limited detection
of dust clouds.
Red (W25, W29) gives maximum contrast of surface features,
enhances fine surface details, dust clouds boundaries, and polar cap
boundaries.
Green (W57) darkens red and blue features, enhances frost patches,
surface fogs, and polar projections.
Blue-Green (W64) helps detect ice-fogs and polar hazes.
Blue (W80A, W38, W38A) and deep blue (W46, W47)
shows atmospheric clouds, discrete white clouds, and limb hazes,
equatorial cloud bands, polar cloud hoods, and darkens reddish
features. The W47 is the standard filter for detection and evaluation of
the mysterious blue clearing.
Magenta (W30, W32) enhances red and blue features and darkens
green ones. Improves polar region features, some Martian clouds,
and surface features.
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Part 2 of this series, describing the more recent history of the
Marswatch project as well as additional details on observing Mars,
will appear in the next IMW Electronic Newsletter.
The A.L.P.O. WWW home page can be found at:
http://www.lpl.arizona.edu/~rhill/alpo/mars.html
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Useful WWW sites:
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Latest MGS images:
http://www.msss.com/mars/global_surveyor/camera/images/index.html
Main MGS Home Page:
http://mars.jpl.nasa.gov/mgs/index.html
Pathfinder Home Page:
http://mars.jpl.nasa.gov/default.html
JPL Mars Missions Page
http://www.jpl.nasa.gov/mars
Mars-98 MVACS Science Payload Home Page:
http://mvacs.ess.ucla.edu/index.html
Mars-01 Athena Science Payload
http://astrosun.tn.cornell.edu/athena/index.html
A.L.P.O. Mars observations:
http://www.lpl.arizona.edu/~rhill/alpo/mars.html
1996-97 Marswatch highlights:
http://mpfwww.jpl.nasa.gov/mpf/marswatch.html
1996-97 Marswatch ftp site:
ftp://marsnt3.jpl.nasa.gov
MarsNet:
http://astrosun.tn.cornell.edu/marsnet/mnhome.html
Mars (and other) Educational Resources Page
http://marswatch.tn.cornell.edu/marsidea
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I will continue to maintain the email distribution list as well
as the various Cornell and JPL Marswatch-related WWW archives. If
you are receiving duplicate copies of this mailing, or you want
your name removed from the distribution list, please send me email.
--Jim
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Jim Bell
Cornell University
Department of Astronomy
Center for Radiophysics and Space Research
424 Space Sciences Building
Ithaca, NY 14853-6801
phone: 607-255-5911; fax: 607-255-9002
email: jimbo@marswatch.tn.cornell.edu
WWW: http://marswatch.tn.cornell.edu
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