Observing Mars in 1997 and MarsWatch newsletter excerpt

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:


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 

Date: Fri, 21 Feb 97 17:18:14 -0800


O-> O-> O-> O-> O-> O-> O-> O-> O-> O-> O-> O-> O-> O-> O-> O->

             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


-                                                                         -
-  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
-                                                                         -

Latest Mars telescopic images continue to arrive in the MarsWatch archive
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:


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
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:


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
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:

19389695.116 km       166862135.249 km       112007028.707 km
12048197.972 mi       103683323.919 mi        69597940.967 mi

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)


More details and progress on the mission can be found at:


Mars Global Surveyor cruise proceeding
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:


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
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


Jim Bell and Bob Anderson

Editors, IMW Newsletter