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New 81P/Wild 2 xyz- Jupiter gravity assists!

Posted: 04.05.2003, 00:28
by JackHiggins
Hey all

I read somewhere that Comet Wild 2 (which Stardust will flyby in 2004) once passed close to Jupiter & had it's orbit modified by the event. Well, I decided to try it out in Celestia, and I discovered it had happened not once, but twice!

In 1927, and 1974, the comet passed very close to Jupiter, and had it's orbit changed from far beyond Neptune, to just past Uranus, and again to it's current orbit. Download the xyz from my site http://homepage.eircom.net/~jackhiggins/celestia/ but first check out the screenshots:

The full xyz:
Image

Flyby in 1974:
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Approach in 1974:
Image

Enjoy!

Posted: 04.05.2003, 12:27
by TERRIER
Nice one Jack!

I also like your Braille asteroid model, which looks a bit like a modern art sculpture that could be called the 'reclining lady'!

Is there anything you could possibly do to the existing Bacchus asteroid model to make it look more curvy and a little less angular?

Regards
TERRIER

Posted: 04.05.2003, 12:44
by JackHiggins
Well... The braille model is based on this:

Image

That's the highest res image available, after a 23km flyby... :( One side of it is completely fictional, so no wonder it looks a bit like a sculpture!!

The existing bacchus model is based on real data & not just artistic, so I guess if it looks a bit angular in Celestia it really is that way... It wouldnt really be realistic if i went & messed around with it!

Posted: 04.05.2003, 15:44
by JackHiggins
Ok, changed my mind! I've smoothed the Bacchus model, it looks almost exactly the same except the edges are now smooth. One quick screenshot:

Image

As always, the site is http://homepage.eircom.net/~jackhiggins/celestia/

(It's at the bottom of the minor moon & asteroid models section)

Posted: 05.05.2003, 00:28
by TERRIER
Cheers JH

Your extremely fast response is very much appreciated, keep up the good work!

Posted: 07.05.2003, 17:59
by praesepe
Jack,

Congratulations for the Braille model, it looks great! It had to be a hard work just to recreate it taking in account that its based on a very low res photograph, but there's something it find strange, It looks like you have applied some kind of shinyness to the model that I find a bit unnatural, at least, for an asteroid :?:

Posted: 07.05.2003, 18:43
by JackHiggins
praesepe wrote:It had to be a hard work just to recreate it taking in account that its based on a very low res photograph
I call it "guesswork" :wink: Actually it's way easier to work from a lo-res photo, you don't have to spend ages working in all the detail!! Braille actually only took me about 20-30mins to do... :)

praesepe wrote:It looks like you have applied some kind of shinyness to the model that I find a bit unnatural, at least, for an asteroid

Yes, that has been a problem... This will be improved greatly in my next few models, and when I have a bit of time i'll fix the one's i've made already.

One more thing, I don't normally do this, but here's a sneak preview of what to expect from me in the near future:
    Halley's Comet nucleus
    Asteroid 5535 Annefrank
    Puck (Uranus)
    Larissa (Neptune)

    Chandra
    Stardust


But you'll have to wait a few weeks before you see any of them...! :mrgreen:

Posted: 07.05.2003, 18:47
by JackHiggins
Actually,

If anyone knows the address of any pictures of the bottom (underneath) part of the Stardust spacecraft, I would be very grateful, as I can't seem to find any myself...

Thanks

Posted: 07.05.2003, 20:12
by JackHiggins
Oh, what the hell- i've put up my Halley, Annefrank, Puck & Larissa models for download, i finished them all 2 days ago anyway... See topic http://63.224.48.65/forum/viewtopic.php?p=14979 or just go straight to my site at http://homepage.eircom.net/~jackhiggins/celestia/ to download!!

praesepe - I haven't been able to fix the shiny asteroid problem, because I don't have 3ds studio max, and that's just the way anim8or saves 3ds models... Sorry bout that... It isn't so obvious in these next few models though, because they're a plain grey colour, not like Braille..

Posted: 08.05.2003, 02:22
by praesepe
JackHiggins wrote:Oh, what the hell- i've put up my Halley, Annefrank, Puck & Larissa models for download, i finished them all 2 days ago anyway... See topic http://63.224.48.65/forum/viewtopic.php?p=14979 or just go straight to my site at http://homepage.eircom.net/~jackhiggins/celestia/ to download!!

Woah! your models look GREAT!! That was a feature which Celestia was lacking of: good quality 3D models. Thank you :)

JackHiggins wrote:praesepe - I haven't been able to fix the shiny asteroid problem, because I don't have 3ds studio max, and that's just the way anim8or saves 3ds models... Sorry bout that... It isn't so obvious in these next few models though, because they're a plain grey colour, not like Braille..
[/quote]

I've edited some of your models (Annefrank, Halley, Puck, Larissa and Braille) and removed that unwanted shine effect and also, reworked the normals to make them smoother (as I did with some of Saturn moon's models that Grant provided some months ago), take a look at the polies!

Braille without shine effect
Image
Larissa Original
Image
Larissa without shine and softened
Image
Puck Original
Image
Puck without shine and softened
Image
Halley Original
Image
Halley without shine and softened
Image
Annefrank Original
Image
Annefrank without shine and softened
Image

Posted: 08.05.2003, 21:30
by JackHiggins
praesepe,

Those new models look great!! Thanks!! :D

I think almost all small objects that can be accurately modelled (at the moment anyway) now have been- just a lot more spacecraft left now!

PS. Check my p.m. if you haven't already

Thanks!