Paul Lavin wrote: > > Run the data loss on the Martian atmosphere composition by me again. When > did this happen? > > P
Thank you for asking! The Viking lander gas chromatography-mass spectrometer (GCMS) data is not available anywhere. What is taken as gospel for the composition at the surface is the paper "The composition of the atmosphere at the surface of Mars," Owen, T. et al; JGR vol 82 1977, p. 4635-4639. The authors were PI's for the Viking I and II GCMS experiments. There is an oft-quoted table of composition - it is missing any error bounds and the numbers don't add up to 100%. Alarm bells should ring! My interest is the amount of molecular oxygen since I did a study for NIAC on extracting this commodity (see http://www.niac.usra.edu under Funded Studies and my name). The number in the JGR paper for oxygen seems to come from Earth-based measurements in 1972, not from Viking as might be inferred from this paper (one must parse the words in this paper like a Clinton speech). In fact, composition will vary following the alternate loss and gain of CO2 to/from the Poles. Back to the lost data. The GCMS data are not archived at the NSSDC (http://nssdc.gsfc.nasa.gov/) where they belong, or at the Planetary Data System (PDS, http://pds.jpl.nasa.gov/) where they also belong. I have had extensive contact with the Atmospheres Node of the PDS, but it has been difficult to raise any interest or concern there. I have confirmed (doubly confirmed, even) that the NSSDC does not have it anywhere such as in a cellar. I have corresponded with Prof. Biemann whose name is listed on the appropriate (but blank) page on the NSSDC website. He confirms that he does not have the data. There is a hardcopy! On a two foot high pile of green decaying computer paper, in octal format. I basically ran out of energy trying to get this data out of the owner's attic and into digital form, but maybe next year. Just yesterday I found out that Mariner 9 photos of Mars are also not available, this from a researcher who wants to compare early 1970's photos with current ones. I have also heard that Viking Orbiter radio occultation data are lost. This last seems astounding since no one could ever suggest that this information was without value. No one seems to take ownership of these problems. The PDS says it does not have funds to recover this data. They do not seem to feel at all guilty about their poor husbandry of this information. As you may note, I have strong feelings on this issue. Chris > > At 08:26 22/11/2002 -0800, you wrote: > > >Anyway, good luck to the Mars Express team, and especially the Beagle II > >team. All ground truth on the composition of the atmosphere is lost > >(the data can't be found), and Beagle II is our chance to get more. > >== == You are subscribed to the Europa Icepick mailing list: [EMAIL PROTECTED] Project information and list (un)subscribe info: http://klx.com/europa/
