Celestia Forums

Hi there! Fenerit & Volcanopele Trojans Blues Band are proud to present Helene:



Helene is not a gracious girl but a desolate piece of rock floating around Saturn.
This 3D model is based upon Cassini images. This moon is very scretched, so the rendering has a little margin of error.

http://marauder.webng.com/files/helene.zip 1.8 Mb
Note: textures are 2k SQUARE; check your Celestia version.

Fenerit: lead modeler and texturing;
Volcanopele: lead orienting and measuring, backing images collection.

Hey, thanks again my friend...

I just love these little surprises...

Much appreciated, Brain-Dead

Great job!

A few comments
1) rotation seems alright, the features shown in your first image could be rotated by about 10 degrees to the west (left) to match the Cassini view.
2) If it helps, the semi-major axes the imaging team measured were a=19.4 km (38.8 km from sub-Saturn to anti-Saturn points), b=18.5 km (37.0 km from leading to trailing points), and c=12.3 (24.6 km from pole to pole).
3) Perhaps the large equatorial bump near 90 W can be lowered just a little bit, not by much, but just a little bit. The satellite can be stretched in the sub-Saturn/anti-Saturn direction, see below from a perspective over 100 W (Sub-Saturn point marked by the red arrow, anti-Saturn point, by definition, in the other direction)

4) With this model, I was able to make animations of the March 2010 and June 2011 flybys of Helene (I guess the 2011 flyby distance was changed in the latest reference trajectory, it used to be the same distance as the 2010 one).

Rev127 March 3, 2010 Flyby
Rev149 June 18, 2011 Flyby

Here there is the 10 degree new model orientation. Model has the new semiaxes. Even though the previous texture matching the model, nonetheless it look too "squashed"; and when I try to map the Cassini's images on the new semiaxes, they doesn't matches at all (at 303W 2.4 S we would to see much more of the model respect to the Cassini's image and at 0W 24N the moon is not "round" as in the image).

http://marauder.webng.com/files/helene_newxyz.zip 414 Kb
No texture.

Hmm, you're right, that is a bit too stretched... I think something halfway between the old model and this new one in terms of stretching the sub-Saturn to anti-Saturn axis, and I think you got it.

Now we just need Pan and Atlas Given the available data, those shouldn't be as hard, nor are their shapes as well constrained. Atlas looks like a giant flying saucer, and Pan looks like a walnut (actually, probably more like a lemon). Maybe like a lemon, but with walnut texture

BTW, fenerit, thank you so much for doing this!

Jason, is the "10" degree orientation right?

hmm, not really, it improved the features on the trailing hemisphere a bit, but it threw everything else off. I think the features seen in the texture in your top image needs to be rotated to the left (to the west) by 10-20 degrees to fit perfectly with the Cassini perspective.