Celestia Forums

Hi. I just downloaded Celestia and, other than the fact that it seems to
regularly lock up my machine, it's amazing. However, I don't know how
to easily get the program to do what's in the demo, and I can't seem to
find any tutorial documentation on how to use the program. For
instance, how does one orbit the earth using the GUI? How does one
place viewpoint on the earth's surface at a particular point, and then "look
outward?"

What I'm after is software that can paint a view of the night sky from my
home, but limit the viewable part of the sky so that the distortion effects
in the window are eliminated. I've seen several programs that sort of do
what I want, but they usually show so much of the sky at once that
the "planisphere" problem arises for me, and it's difficult to correlate what
I see outside to what I see in the "circle" or "oval" that covers the entire
sky. The trouble is that when you look up, your peripheral vision only
takes in a small portion of the sky, and what I want is software that can
center a particular star in the window from a particular lat/long, and then
show the sky "as if from binoculars," but with star and/or constellation
labels, planetary motion lines, etc. so you can get a true sense of what
you're looking at. I then want to be able to move the direction of view as
if I was moving my head. (sort of a means of "superimposing" data onto
one's vision in a simulated sky...)

Can anyone tell me if Celestia can do this, or if not, recommend software
that can?

Thanks in advance,
Will Sadkin

wsadkin wrote:Hi. I just downloaded Celestia and, other than the fact that it seems to
regularly lock up my machine, it's amazing. However, I don't know how
to easily get the program to do what's in the demo, and I can't seem to
find any tutorial documentation on how to use the program. For
instance, how does one orbit the earth using the GUI? How does one
place viewpoint on the earth's surface at a particular point, and then "look
outward?"

It's not as easy as it should be, unfortunately . . . You can use Goto Object in the Navigation menu to set your location to a latitude and longitude on a planet's surface and then use the mouse to orient your view so that you're looking upward.

What I'm after is software that can paint a view of the night sky from my
home, but limit the viewable part of the sky so that the distortion effects
in the window are eliminated. I've seen several programs that sort of do
what I want, but they usually show so much of the sky at once that
the "planisphere" problem arises for me, and it's difficult to correlate what
I see outside to what I see in the "circle" or "oval" that covers the entire
sky. The trouble is that when you look up, your peripheral vision only
takes in a small portion of the sky, and what I want is software that can
center a particular star in the window from a particular lat/long, and then
show the sky "as if from binoculars," but with star and/or constellation
labels, planetary motion lines, etc. so you can get a true sense of what
you're looking at. I then want to be able to move the direction of view as
if I was moving my head. (sort of a means of "superimposing" data onto
one's vision in a simulated sky...)

It sounds like what you want to do is simply decrease the field of view. Use the . and , keys to adjust the field of view.

--Chris

Yeah, I had figured those things out since I posted, but 2 things still
elude me:

1) you have to specify a distance, but it's from the center of the
object, so it's really difficult to "stand" on the surface.

2) There's no notion of "north, south, east or west", nor is it easy to
see what part of the sky you're looking from.

If there were special modes for Earth at least, that allowed you
to get at least "center of view" azimuth and compass heading, it
would be a lot easier to "navigate" the night sky...

Any chance these are hidden options?

Also, it would be really cool if you could "stand", facing outward,
and then have time elapse to show the progress of the moon
across the sky. Any chance this is doable?

Finally, is there an archive of "movies" people have made somewhere
you can download them?

Thanks again,
/Will

Will,

1) One way is to do the final positioning interactively. Using the mouse, Celestia tends to limit your motion to approaciing the surface of an object. (This doesn't quite seem to be the case for the Earth. I suspect that's because it's oblate and not a perfect sphere.) It's easy to "stand" a few tens of meters above the surface. The Locations menu can be used to memorize that location.

I usually "skim in" to a location on the surface of an object by using a combination of the right-mouse-button, wheel and the up & down arrow keys.

Once you're at the appropriate place on the surface, the left and right arrow keys can be used to get a level orientation and then the numeric pad can be used to took around (4&6) and up and down (2&8).

2) Sure there is: turn on rendering of the "celestia grid". It shows RA and Dec. That makes it quite easy to locate Polaris if you're in the northern hemisphere, for example. I agree it'd be nice to have an altazimuth coordinate display, though.

( Hmm. One way to do it might be by creating a high resolution cloud texture at a very high altitude, consisting of appropriate lines instead of irregular clouds. Getting it centered over your desired position might be a bit tricky.)

If you have "sync orbit" enabled. your position on the surface will stay the same. You can then increase the rate of time passing and watch the sky turn overhead.

While there are quite a few static images in various Galleries, I don't know of any collection of movies.

I hope this helps.

Will, This is probably heresy , but have you tried Starry Night? It will show you what is going on in the sky from where you are. BUT, it won't take you to a black hole or to Endor! Or allow you to watch Saturn from Titan!

Hi everybody Celestia is a fabulous tool i discover some month ago but for doing what you want there is another software which is complementary to Celestia for viewing exact sky from everywhere on Earth (Lat. Long.) at every date and time. It's Stellarium, a virtual planetarium. It renders 3D photo-realistic skies in real time. With stellarium, you really see what you can see with your eyes, binoculars or a small telescope. And over all, it's free and run under Windows, MacOS X, Linux Mandrake !!!

Download it at : stellarium.free.fr

Thanks for all the work from the guys on this forum, I will soon post some little work from myself as contribution to this incredible tool called Celestia.

I would like to see you make an addition to the overall enviroment in Celestia making it possible to view locations from the surface of any planet similar to that software...That would be very cool...