Posts by volcanopele

by volcanopele
19.04.2010, 19:47
Forum: Celestia Users
Topic: Celestia movie synced Cassini Wide Angle sequence
Replies: 8
Views: 3760

Re: Celestia movie synced Cassini Wide Angle sequence

No, Calypso (and the other trojan moons) has a tadpole orbit, which is the similar to a horseshoe orbit, except Calypso just librates around the L5 point, rather than bouncing between L4 and L5 like Epimetheus. That means that sometimes Calypso is further away or closer to Tethys or Saturn.
by volcanopele
16.04.2010, 19:47
Forum: Celestia Users
Topic: Celestia movie synced Cassini Wide Angle sequence
Replies: 8
Views: 3760

Re: Celestia movie synced Cassini Wide Angle sequence

No that is Calypso. Celestia has it wrong as Calypso definitely doesn't have a simple Keplerian orbit. At some point I need to create a youtube video showing that.

http://en.wikipedia.org/wiki/Horseshoe_ ... pole_orbit
by volcanopele
15.04.2010, 07:09
Forum: Celestia Users
Topic: Celestia movie synced Cassini Wide Angle sequence
Replies: 8
Views: 3760

Re: Celestia movie synced Cassini Wide Angle sequence

Not sure what the UFO thing is about (can't read italian), but the moons seem to be identified correctly. Some of the position differences are due to your version of Celestia using Keplerian elements for Saturn's small moons, which isn't quite correct due to the effects of nearby, larger moons. The ...
by volcanopele
12.03.2010, 22:49
Forum: Celestia Users
Topic: My Handy "60-DEGREE RULE" for 1.4.1
Replies: 4
Views: 2735

Re: My Handy "60-DEGREE RULE" for 1.4.1

hmm, wouldn't this give you the radius of the star, not the diameter?
by volcanopele
10.03.2010, 19:15
Forum: Bugs
Topic: 1.6.0 "Lock" Behavior
Replies: 11
Views: 4345

Re: 1.6.0 "Lock" Behavior

I have encountered this issue when making movies of spacecraft fly bys. In my movie of Jupiter Europa Orbiter flybys of Io:

http://www.youtube.com/watch?v=FRpSgmgfCes

You can see little stutter rotations of Io, which is me trying counter act the flips.
by volcanopele
06.03.2010, 22:27
Forum: Add-on releases
Topic: Io Nightside plus USGS basemap
Replies: 18
Views: 5897

Re: Io Nightside plus USGS basemap

hmm, you are right danielj, I thought I had extended it to 16k, but it is actually 8k (8192x4096)... Well, you aren't actually missing much. Maybe a bit on the southern, sub-Jupiter hemisphere. The original image is 11445x5723.
by volcanopele
06.03.2010, 19:30
Forum: Add-on releases
Topic: Io Nightside plus USGS basemap
Replies: 18
Views: 5897

Re: Io Nightside plus USGS basemap

Would there be a way to script it so that at some times it is random, other times there are set plumes at locations? We have seen plumes at 24 volcanoes. As I said in my previous post, some are persistent, meaning that every time we have looked for it, the plume was there. Prometheus, Kanehekili, Ma...
by volcanopele
01.03.2010, 16:10
Forum: Add-on releases
Topic: Io Nightside plus USGS basemap
Replies: 18
Views: 5897

Re: Io Nightside plus USGS basemap

Actually, the USGS basemap is 16k IIRC, expanded from 11445x5723 [ http://astrogeology.usgs.gov/Projects/JupiterSatellites/io.html ]. I used a virtual texture for Io in this case. As far as the volcanoes go, keep in mind that only about ~24 plumes have ever been observed on Io, with 6-8 observed at ...
by volcanopele
28.02.2010, 20:13
Forum: Add-on releases
Topic: Io Nightside plus USGS basemap
Replies: 18
Views: 5897

Re: Io Nightside plus USGS basemap

The map uses the USGS basemap and basically "paints" dark paterae floor terrain or volcanoes that have been seen as hotspots. For volcanoes where we have high resolution thermal data, like the Amirani data you linked to, I painted only those areas where thermal emission was seen. I'll be h...
by volcanopele
23.02.2010, 05:32
Forum: Add-on development
Topic: Jupiter Europa Orbiter
Replies: 0
Views: 1803

Jupiter Europa Orbiter

As I mentioned in a thread over on the Add-on releases sub-forum , I created a video showing the four Io flybys currently in the baseline trajectory for the Jupiter Europa Orbiter , NASA's mission to orbit Europa in the 2020s. I have created a small add-on with this trajectory. Please note a few thi...
by volcanopele
22.02.2010, 09:38
Forum: Add-on releases
Topic: Io Nightside plus USGS basemap
Replies: 18
Views: 5897

Io Nightside plus USGS basemap

Yesterday, I posted a video showing the four Jupiter Europa Orbiter encounters with Jupiter's moon Io on Youtube: http://www.youtube.com/watch?v=FRpSgmgfCes The video included my USGS basemap texture plus a nightside texture that has glowing hotspots from active volcanoes. I've put these together in...
by volcanopele
13.02.2010, 07:18
Forum: Physics and Astronomy
Topic: Celestia on official Cassini website
Replies: 4
Views: 2877

Re: Celestia on official Cassini website

No, I don't work at CICLOPS, which is the team leader's Carolyn Porco's little shop; I work for one of the other Imaging Team members. However, one of my tasks is writing up the Looking Ahead articles for each orbit and working on the graphics, which are generally created in Celestia with some mild ...
by volcanopele
12.02.2010, 18:56
Forum: Physics and Astronomy
Topic: Celestia on official Cassini website
Replies: 4
Views: 2877

Re: Celestia on official Cassini website

Yep, they sure are :D :wink: We post previews of ISS (and occasionally other instruments) observations for each Cassini orbit. Celestia is used simply because it is the easiest for me to update (in terms of spice kernels and textures) and the graphics are a lot better.
by volcanopele
30.12.2009, 17:52
Forum: Physics and Astronomy
Topic: Ganymede completely mapped
Replies: 4
Views: 2569

Re: Ganymede completely mapped

But this texture is TOO OLD,more than 1 year of age.I understand that astronomers completed Ganymede map recently... The map that was completed would not be a new texture but is a geologic map based on a USGS basemap created several years ago. I guess you could create an alternative texture from it...
by volcanopele
10.11.2009, 18:14
Forum: Physics and Astronomy
Topic: S/ 2009 S 1
Replies: 2
Views: 3420

S/ 2009 S 1

This is the Celestia definition I use for this recently announced satellite of Saturn, S/ 2009 S 1 that seems to work reasonably well given the available observation of it: "2009 S1" "Sol/Saturn" { Class "minormoon" Texture "asteroid.jpg" Radius 0.15 Elliptica...
by volcanopele
31.10.2009, 09:26
Forum: Ideas & News
Topic: Particle systems revisited
Replies: 24
Views: 14376

Re: Particle systems revisited

One change that Chris and I have discussed and that I would like to see included in particle systems, is some sort of user-definable phase function. Currently by default, Celestia assumes that objects are either emitters of light (like stars) or if they reflect light, they are back-scattering, meani...
by volcanopele
07.10.2009, 20:58
Forum: Add-on development
Topic: Helene 3D CMOD model
Replies: 6
Views: 4013

Re: Helene 3D CMOD model

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.
by volcanopele
07.10.2009, 20:39
Forum: Add-on development
Topic: Helene 3D CMOD model
Replies: 6
Views: 4013

Re: Helene 3D CMOD model

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...
by volcanopele
07.10.2009, 08:06
Forum: Add-on development
Topic: Helene 3D CMOD model
Replies: 6
Views: 4013

Re: Helene 3D CMOD model

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),...
by volcanopele
05.10.2009, 01:28
Forum: Add-on development
Topic: Saturn Rings
Replies: 4
Views: 3306

Re: Saturn Rings

Great to see an unlit-side rings texture coming around!

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