Celestia Forums

I too thought that the moon in background was Tethys. But it is actually Rhea. On February 20th Dione passed over Rhea, and on 21th over Tethys. These images were taken on 20th February. Tethys was the on the other side of Saturn. It fooled me too, when this came up in the Bad Astronomy forums! The...

I wonder: Could refraction in clouds of other than water droplets, say methane, also form a rainbow? Probably. Also, this site has some interesting speculations about ice-crystal halos from substances other than water, as might conceivably exist on Mars, the upper atmosphere of Titan and the giant ...

Probably the best way to answer this question is to look at the pictures. It appears to me that there's some fuzz there, just caused by the angular size of the Sun as seen from Saturn.

This actually brings up one of my hobbyhorses, which is that when thinking about extrasolar planetary systems we really ought to be extrapolating not from our own solar system, but from what we know about extrasolar multiple star systems. We know that, at least for the brighter stars, complex bound ...

Yeah, after I posted that I was thinking maybe the background is either the E ring, or zodiacal light.

The background has strange specks in it that might be overexposed stars, but with exposures this long you usually see cosmic-ray glitches all over as well.

If a slowing of major Celestia development has got you down, there's always the fun of tweaking it yourself to accommodate new scientific discoveries. I've been following the Cassini Saturn mission closely and am amazed at the speed at which Steve Albers is able to incorporate new images into his mo...

I've had no particular problems with 10.3.8 (dual 2002 Quicksilver G4, Radeon 7500) running with the 1.4 prerelease. The OS updates include bug updates to Nvidia and ATI drivers, so it's probably a good idea to get them. Lately, once in a blue moon I can even see the shadow of Saturn on its rings, t...

I suppose that these occultations are going to become more common as Cassini moves down into the ring plane. From September through mid-2006 it will be orbiting right in the plane of the rings and of most of the icy moons, so there will be no pretty ring pictures for a while, but lots of moon encoun...

Some cosmologists have proposed the weird idea that even if space is flat or negatively curved, we could live in a "small" finite universe (that is, small compared to the speed of light times the age of the universe). It wouldn't be hyperspherical, however. Such a universe could be connected to itse...

Here's a really splendid Enceladus mosaic.

andersa wrote:It's Saturnshine on the left, but the background is overexposed space rather than Saturn itself.

If that is so, how could the dark part of Enceladus possibly be that much darker than space?

Whatever happens on the screen is reflected on the surface of Earth! I didn't check, but I assume the cube had an ATi Rage 128, the facotry default installed. It was running 10.3.7 This is a longstanding problem with Celestia in recent Mac OS X versions; it is probably a bug in Apple's "Quartz Extr...

Great job, dirkpitt. It's nice finally having the object/location browser! Unfortunately, now that bump maps and normal maps actually work on my Mac (they are beautiful), my need for a more powerful video card becomes all too apparent... the gap between what it's capable of doing at all and what it'...

Would the IR3/green/UV3 be what you'd see if you could see Ultraviolet and Infrared as well as normal colours? Because if we could, the visible color spectrum would probably just spread into these types of light. I suppose it's a bit like what you'd see if you could see some UV and infrared, but yo...

That straight line, I forget if there are any higher resolution images of that region. If not, could it be possible that it is some sort of artifact of the image? Perhaps a fault in the data? Or are we indeed looking at a feature that has shown some topography? I don't know what it is, but it's rea...

It is telling that the colours that you "brung out" (I love you for that phrase :) ) are primary or secondary colours, green and magenta and blue, and that they mostly occur near the limb or terminater. If I saw these while putting the original RGB channels together I would have been sure that eith...

Ah, I see everyone's way ahead of me in the "Enceladus" thread... never mind then.

My attempts at colorizing Cassini Rhea pictures: http://world.std.com/~mmcirvin/rhea_true_color.jpg RGB visible-light composite. I don't have any means of calibrating these pictures precisely, of course, but I suspect this is pretty close to a natural color view. Rhea is pretty gray. http://world.st...

Does it mean we can add the line : Oblateness 0.09 for mimas in the solarsys.ssc file ? That wouldn't be quite right, since Mimas isn't symmetric about its rotation axis, and is closer to a prolate spheroid than an oblate one. Giving it a negative oblateness should elongate it north-south, but unfo...

...So, apparently one of the problems the Huygens probe had was that its Sun sensor couldn't get a lock on the Sun's position once it was inside the haze layer, which meant that the people piecing these pictures together into mosaics don't have good orientation data. This may not have any bearing on...