Celestia 1.3.2

[mmcirvin]

I missed this a little while ago: the latest release of the extremely cool space simulator Celestia, version 1.3.2, now has a build for Mac OS X, though the official Web site doesn't say so. The tireless person who does most of the Mac porting seems to regard this build as experimental, but it works pretty well except for a few problems with persistency of preferences, some of which existed in previous versions as well.

(Celestia feature development tends to be X11- and Windows-centric, and the Mac version is very much a port, so it often lags about a minor version update behind and lacks a few interface features. Meanwhile, Apple just dropped a bombshell by using Celestia as an example for their Shark code optimization tool, though their sped-up version just runs the scripted demo and it's hard to say whether the optimizations could get back into the trunk.)

Version 1.3.2's biggest enhancements over 1.3.1, as far as I can tell, are to the default solar system dataset, which includes improved Saturn and Titan textures based on Cassini data and an excellent Cassini/Huygens model with complete mission trajectory, so you can follow along with its encounters.

The shadow of Saturn's rings on the planet was darkened for visual consistency with Cassini pictures. It's amazing how many people reported the mysterious dark bands on Saturn as a bug and experimented with hacks to make them go away.

Comments

[mmcirvin.livejournal.com]

...As always, if the Moon and Mars look rainbow-colored, go into CelestiaResources/data/solarsys.ssc and comment out all the references to BumpMap.

If it's planets you want...

[sunburn.livejournal.com]

both NASA's freebie WorldWind (http://learn.arc.nasa.gov/worldwind/) and Google's affordable subscription-based Keyhole (http://www.keyhole.com/?promo=app-en-us) (free 7-day trial with watermark) satellite-picture-viewer doohickeys have means of covering Mars as well as Earth. In Worldwind's case it's a matter of downloading the Mars satellite cache, which can be seen in this thread (http://learn.arc.nasa.gov/worldwind/forums/index.php?showtopic=514) about the recurring server-load problem which is finally clearing up a bit. Keyhole's Mars coverage only seems to come with the "NV" version (http://www.keyhole.com/body.php?h=products&t=keyhole2NV), which requires nVidia graphics cards; go figure.

Keyhole is the superior product with some great features, including address searching so you can run down your childhood homes in minutes instead of trying to remember which streets you rode your bike on when you were 10, but I think WorldWind's clean interface is a little friendlier-- it's pretty slim on features, but if you know where to find something, WW will get you there. The other problem is that WW's client is huge, while KH's client is less than 10 MB.

Either way, try not to download either app within an hour of going to bed. Or an important meeting, since I take it you don't have at home any Windows machines that're likely to be up to snuff in the graphics department. Sorry Tennessee!

Re: If it's planets you want...

[sunburn.livejournal.com]

Oh yeah, WW covers the whole earth sans ocean at Landsat ~1 meter resolution using oldish images from Landsat and USGS, while KH covers the whole earth at unremarkable resolution and covers major population areas at head-popping resolution using recent images. My building, which is close to downtown Seattle, can be seen with 1' resolution, and the images are only 2 years old!

Re: If it's planets you want...

[mmcirvin.livejournal.com]

For a while, the service Yahoo Maps was using had aerial photos as well; it was pretty easy to pick out my house.

[mmcirvin.livejournal.com]

Chris Laurel really needs to update his screenshot gallery (http://shatters.net/celestia/gallery.html), since Celestia is capable of far more spectacular-looking views than that by now. Maybe I should generate some suggested replacements fo r him.

[mmcirvin.livejournal.com]

...It's also kept up well with the pace of astronomical discoveries. One of the most remarkable things added to the database is the mysterious "inner Oort Cloud" object Sedna, occasionally touted as a tenth planet (though its size is subject to dispute). Sedna's orbit is so large that if you turn on orbit displays and zoom in on the solar system from afar, the orbit pops up as a visible ellipse while the positions of the nearby stars are still visibly shifting, Star Trek-style. And Oort Cloud comets proper are supposed to have orbits even bigger than that.

[mmcirvin.livejournal.com]

Another thing: I didn't actually realize this until just now (and I don't think it was always true), but Mac Celestia now supports .dds textures, at least with my video card (which is pretty old and crappy by modern standards). These are files containing multi-resolution textures, in such a manner that you can display frightfully high-resolution surface maps without blowing out your video card's memory.

There aren't any .dds textures that ship with the default install, because they are enormous files. But the Celestia Motherlode (http://www.celestiamotherlode.net/) has gorgeous ones for Earth, Mars and a few other objects (including a few of the icy moons of Saturn, still from Voyager maps so far-- I was motivated to poke around because Cassini recently took some very nice pictures of Rhea and Tethys, so before long there ought to be better ones).

[mmcirvin.livejournal.com]

...What's missing is .dds coverage of the Galileans. I think the ones that ship with the program are made from Björn Jónsson's maps (http://www.mmedia.is/~bjj/planetary_maps.html), which are terrific, but I can't use his full-resolution versions because whenever two or more of the moons are in frame at once, the program runs into trouble.