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Fraser
2004-Nov-04, 06:04 PM
SUMMARY: As the ESA's Huygens probe makes its descent into Titan's thick atmosphere in January, telescopes here on Earth will be watching carefully to help understand the global condition of the moon's atmosphere. Cassini's job will be to communicate with Huygens, so it won't actually be able to take pictures of the moon while it's performing this vital task, so it's up to the Earth-based telescopes. There's a remote possibility that Hubble or the giant 10-metre Keck observatory will see a tiny fireball as Huygens enters Titan's atmosphere.

What do you think about this story? Post your comments below.

om@umr.edu
2004-Nov-04, 06:19 PM
An interesting story!

Where can we find more details about the measurements?

What instruments are on the probe?

Will they be able to measure the composition of Titan's atmosphere?

Will they be able to measue the abundance of individual isotopes?

With kind regards,

Oliver
http://www.umr.edu/~om

antoniseb
2004-Nov-04, 06:32 PM
Originally posted by om@umr.edu@Nov 4 2004, 06:19 PM
What instruments are on the probe?
The Cassini website has all that information on it. It has an instrument called the Gas Chromatograph Mass Spectrometer of which they say this:

This instrument will be a versatile gas chemical analyzer designed to identify and measure chemicals in Titan's atmosphere. It will be equipped with samplers that will be filled at high altitude for analysis. The mass spectrometer will build a model of the molecular masses of each gas, and a more powerful separation of molecular and isotopic species will be accomplished by the gas chromatograph. During descent, the GCMS will also analyze pyrolysis products (i.e., samples altered by heating) passed to it from the Aerosol Collector Pyrolyser. Finally, the GCMS will measure the composition of Titan's surface in the event of a safe landing. This investigation will be made possible by heating the GCMS instrument just prior to impact in order to vaporize the surface material upon contact.
See this site for more details:
ESA Huygens GCMS (http://sci.esa.int/science-e/www/object/index.cfm?fobjectid=31193&fbodylongid=736)

The Gas Chromatograph and Mass Spectrometer (GCMS) will measure the chemical composition of Titan's atmosphere from 170 km altitude (approx. 1 mbar) to the surface (approx. 1.5 bar) and determine the isotope ratios of the major gaseous constituents.

Matthew
2004-Nov-05, 09:02 AM
Does anyone know of what sort of resolution we could expect from the Hubble or the Keck telescopes? Would the fire streak be one pixel at highest resolution?

antoniseb
2004-Nov-05, 02:04 PM
Originally posted by matthew@Nov 5 2004, 09:02 AM
Does anyone know of what sort of resolution we could expect from the Hubble or the Keck telescopes? Would the fire streak be one pixel at highest resolution?
The streak would be far less than a pixel wide, but would probably extend over several pixels in length.

om@umr.edu
2004-Nov-05, 02:40 PM
Thanks, Anton, for information on The Gas Chromatograph and Mass Spectrometer (GCMS) that "will measure the chemical composition of Titan's atmosphere . . . and determine the isotope ratios of the major gaseous constituents."

I look forward to seeing the results. I hope the raw data will also be made available to the public.

At the 1998 AAS meeting in Washington, DC, Dr. Daniel S. Goldin ordered the release of raw data from the mass spectrometer on the Galileo probe into Jupiter's atmosphere [D. S. GOLDIN "Future of Space Science" (Speech at the 191st Meeting of the American Astronomical Society, Washington, D.C., January 7, 1998) C-SPAN Tape 98-01-07-22-1, Purdue University Public Affairs Video Archives, Item 98526].

My students used those results to determine the isotope ratios of primordial H and He in Jupiter.

http://web.umr.edu/~om/abstracts/nolte_lietz.pdf
http://www.umr.edu/~om/abstracts/nolte_lietz.ps

They also found excess Xe-136 in Jupiter, just like the excess Xe-136 in "strange xenon" that accompanies primordial He in "so-called" interstellar diamonds of meteorites.

http://www.umr.edu/~om/abstracts2001/windl...leranalysis.pdf (http://www.umr.edu/~om/abstracts2001/windleranalysis.pdf)

Data from the Titan atmosphere may further resolve isotope heterogeneities in prenatal material of the solar system from that carried in by interstellar grains.

With kind regards,

Oliver
http://www.umr.edu/~om

antoniseb
2004-Nov-05, 02:53 PM
Originally posted by om@umr.edu@Nov 5 2004, 02:40 PM
I look forward to seeing the results. I hope the raw data will also be made available to the public.
Same here. I hope the data comes out a little faster than what we've seen with the WMAP data. The results should be less complicated, and easier to publish.

On the whole I expect the Titan data to show more fractionation away from the ISM isotope ratios than Saturn shows, but less than the terrestrial and near-Earth meteorite values. It will be interesting to see where it fits in.