From: Jan Wee <jwee@mail.arc.nasa.gov>
Subject: Observing Mars in 1997 and MarsWatch newsletter excerpt
Date: Tue, 04 Mar 1997 15:02:15 -0600
Dear discuss-lfm members,
March is a particularly good month for Mars watching and Sky Online's
web site has a great resource to tap called "Observing Mars in
1997" by Alan MacRobert. You can find info on:
How to Observe
Using the Mars Map
Things to Watch (Albedo Features, North Polar Caps, Clouds)
WWW links
and images and animations at this URL:
http://www.skypub.com/whatsup/mars97.html
Don't forget the Marswatch Project site which has a unique group
of Mars images from Amateur and Professional MarsWatch participants.
The following is an excerpt taken from the Marswatch Newsletter and
contains several useful URL's.
Happy Mars Watching! (Along with Comet Hale-Bopp)
Jan Wee, moderator
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Subject: THE INTERNATIONAL MARSWATCH ELECTRONIC NEWSLETTER for Feb-97
Date: Fri, 21 Feb 97 17:18:14 -0800
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O-> O-> O-> O-> O-> O-> O-> O-> O-> O-> O-> O-> O-> O-> O-> O->
THE INTERNATIONAL MARSWATCH ELECTRONIC NEWSLETTER
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Volume 2; Issue 4 (file imw.feb97)
February 1997
Circulation: 661
<-O <-O <-O <-O <-O <-O <-O <-O <-O <-O <-O <-O <-O <-O <-O <-O
HAPPY MARS APHELION!
CONTENTS-------------------------------------------------------------------
- -
- Latest telescopic images of Mars continually arriving -1
- Mars Pathfinder Web user statistics -1
- 1996-97 HST Mars images available on-line -2
- Mars Pathfinder successfully launched and on its way -2
- Mars Global Surveyor cruise proceeding -2
- Mars '96 Launch ends in tragedy -3
- List of MarsWatch-related WWW pages and addresses -3
- -
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Latest Mars telescopic images continue to arrive in the MarsWatch archive
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A number of observers from around the world have begun posting their
CCD images and drawings of Mars on the MarsWatch WWW archive page
(WE THANK YOU!!). These images provide the most up-to-date information
available on the state of the Martian surface and atmosphere (some images
are even posted on the day after the observations were made!). Much of
Mars is chilled to its lowest temperatures because the planet is at aphelion,
or its farthest point from the Sun. Most observers are reporting extensive
equatorial and orographic (mountain-related) cloud activity, as well as the
continuing retreat of the north polar cap as the northern hemisphere of
Mars transitions into summer. No global dust activity has been reported,
although occasional evidence for local dust storms has been reported by
several observers as well as the Hubble Space Telescope (HST). To view
or download images from the archive, go to URL:
http://mpfwww.jpl.nasa.gov/mpf/marswatch_images.html
Mars Pathfinder Web user statistics
-----------------------------------
Total number of accesses = 323335
Total number of visits = 21447 (A visit is a group of accesses
separated by 180s.)
Total number of bytes transferred = 2174134321 (2.17 Gb)
Number of files accessed on this server = ~400
Highest number of hits per day = 1/30: 53124
Lowest number of hits per day = 2/1: 40142
MPF-Status E-mail list: 3407 subscribers
Access per day = 46190
Visits per day = 3063
1996-97 HST Mars images available on-line
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HST has been imaging Mars between September 1996 and January
1997 as part of a long-term monitoring program by Phil James
and colleagues. Color composites of these HST images can now
be found on-line at the URL:
http://marswatch.tn.cornell.edu/hst96-97.html
Because of the upcoming Space Shuttle servicing mission to HST,
no more HST Mars observations are being planned until mid- to
late-March, right around opposition. Thus, there is an important
need for high-quality groundbased observations to fill this gap in
HST time coverage.
Mars Pathfinder successfully launched and on target
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The Mars Pathfinder spacecraft was successfully launched from Cape Canaveral
on a Delta rocket in the early morning hours of December 4. The launch was
spectacular and completely "nominal" in NASAspeak. The spacecraft successfully
performed its first two trajectory correction maneuvers, and is proceeding on
course for a July 4 landing in the mouth of the Ares/Tiu Valles outflow channel
on Mars. On February 3, Trajectory Correction Maneuver #2 was successfully
completed. The purpose of this maneuver was to clean up TCM-1 execution
errors and had a magnitude of about 1.6 m/s. The maneuver consisted of
two parts, an axial component of 1.5 m/s and a lateral component of 0.1 m/s.
All spacecraft subsystems performed as expected, and the resulting maneuver
execution error was less than 2%. The spacecraft was turned back to Earth
after the maneuver, and will remain in this attitude until late March.
Congratulations to the Pathfinder team for a great start to the mission!
Distances and Velocities of MPF as of: 1997-FEB-06 12:00:00 UTC:
DISTANCE TO EARTH DISTANCE TO SUN DISTANCE TO MARS
19389695.116 km 166862135.249 km 112007028.707 km
12048197.972 mi 103683323.919 mi 69597940.967 mi
GEOCENTRIC VELOCITY HELIOCENTRIC VELOCITY AREOCENTRIC VELOCITY
5.323 km/sec 30.064 km/sec 16.698 km/sec
11908.018 mph 67250.962 mph 37351.903 mph
TIME TO MARS: -148d 04:51:11.0
ONE-WAY LIGHT TIME: 00:01:04.7
DISTANCE TRAVELED SINCE INJECTION: 178352044.5156 km (110822822.4963 mi)
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More details and progress on the mission can be found at:
http://mpfwww.jpl.nasa.gov/
Mars Global Surveyor cruise proceeding
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The Mars Global Surveyor spacecraft continues to perform well
on its cruise to Mars. The latest estimate for orbital insertion
date is September 12, 1997. Flight engineers continue to experiment
with ways to resolve the slight misalignment of one of the spacecraft's
solar panels, even though this misalignment is not thought to threaten
the success of the mission. The initial checkout of the MGS science instruments
went well, with no anomalies reported. Check out their new webpage for
more details, see:
http://mgs-www.jpl.nasa.gov/mgs-home.html
Mars '96 Launch ends in tragedy
-------------------------------
The Mars exploration program had a major setback in November as the
Russian Mars '96 mission ended in failure hours after launch, when
the spacecraft failed to attain Earth orbit. The detailed explanation
for the launch failure has not yet been determined. Scientists from
Russia, many ESA member states, and the U.S. were involved in the
ambitious project. Given the financial hardships in Russia and other
nations, it is not clear whether enough funding can be secured to mount a
follow-on recovery mission for many years.
List of MarsWatch-related WWW pages and addresses
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Here is a list of some of the URLs that you can link to in order to
find more information and background on Mars and the MarsWatch project:
1996-97 MarsWatch Web site: http://mpfwww.jpl.nasa.gov/mpf/marswatch.html
MarsWatch Goals: http://astrosun.tn.cornell.edu/marsnet/imw/marswatch96.info
HST Observations and MarsWatch: http://mpfwww.jpl.nasa.gov/mpf/hst.html
1996-97 HST Mars images: http://marswatch.tn.cornell.edu/hst96-97.html
Other 1996-97 Mars images: http://marswatch.tn.cornell.edu/mars.html
1994-95 HST Mars image archive: http://marswatch.tn.cornell.edu/hst_archive.html
1994-95 MarsWatch Web site: http://astrosun.tn.cornell.edu/marsnet/mnhome.html
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Jim Bell and Bob Anderson
Editors, IMW Newsletter
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