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Posted by: volcanopele Jun 20 2005, 10:02 PM

I am trying to track down the location of Hyperion features listed on the Planetary Names website

http://planetarynames.wr.usgs.gov/jsp/FeatureTypesData2.jsp?systemID=6&bodyID=56&typeID=9&system=Saturn&body=Hyperion&type=Crater,%20craters&sort=AName&show=Fname&show=Lat&show=Long&show=Diam&show=Stat&show=Orig

I've been able to track down a map of Hyperion with some features names:

http://www.etsimo.uniovi.es/solar/r/sat/hyperionmap.jpg

but it doesn't have the crater called Helios. Even using the lat/lons on the feature list won't help since the craters the map does have don't correlate with the lat/lons for those crater in the list. Any help on trying to confirm the identities of these craters and identifying Helios would be helpful.

Posted by: Phil Stooke Jun 20 2005, 11:37 PM

Volcanopele... the USGS name list assumed a different (arbitrary) coordinate system as the rotation state was unknown at the time. But plot those names on a grid and you can see how they fall. Tayfun Ofer's map was made with the coordinate system I prepared from the Cornell. U. study on rotation (see Icarus Vol. 117), which gave Hyperion a slow long axis mode rotation with large-angle rapid precession, like Comet Halley's nucleus. Peter Thomas also has shape model based on this.

Ofer put the names on that map independently and omitted the name Helios. I believe it refers to the biggest crater seen well in Voyager images, and in these latest pics.


The names were shown in the 1984 USGS annual gazetteeer of planetary nomenclature, open File Report 84-692, and in a paper by yours truly in Earth, Moon and Planets, v. 74, pp. 61-83, 1996.

Phil

(NOTE: edited heavily after I got back to my office and could look things up)

Posted by: volcanopele Jun 21 2005, 04:09 PM

Just checking to see if I got this correct:

Posted by: Phil Stooke Jun 21 2005, 05:04 PM

That's the one!

Phil

Posted by: volcanopele Sep 28 2005, 05:29 PM

Just a note that Peter Thomas' 1995 paper on the rotation, shape, and geology of Hyperion has Meri, Jarilo, and Bahloo identified, if anyone is try to figure out what features are which. Also note that my identification of Helios is incorrect (not mentioned in the article, but I thought I'd point that out myself).

Posted by: Tayfun Öner Sep 28 2005, 05:41 PM

Volcanopele: I made that map 5 years ago, it is based on Phil Stooke's shape model and although I don't remember exactly I placed the names according to a figure in Peter Thomas' article, that's why it does not include Helios and lat-long may be different from IAU list.

Posted by: volcanopele Sep 28 2005, 06:05 PM

No problems. The coordinate system is no longer good anyway for our purpose... What may need to be done is to just accept some arbitrary coordinate system and stick with that for mapping purposes. Definitely will still require a good shape model.

Posted by: SigurRosFan Sep 28 2005, 06:17 PM

Sharper Hyperion Features: