Celestia Forums

Is it possible to set in Celestia how the sky will look like at a certain date and FROM A CERTAIN LOCATION (latitude and longitude) on Earth ? (like from a particular city, etc)

Yes but only with a script... I have done one for Paris (where I live).

Use the "gotolonglat" command.

Kendrix:
Could you send me the script?
And how do you use the "gotolonglat" command? (for example for Paris)
Thanks

Here is my script :
{
select { object "Sol/Earth" }
follow {}
gotolonglat { time 1.0 distance 1.003 longitude 2.0 latitude 48.0 } # Paris
wait { duration 2.0 }
setambientlight { brightness 1.0 }
select { object "Polaris" }
center {}
wait { duration 2.0 }
select { object "Sol/Earth" }
}

I first select earth. Then in 1 second I go to 2° longitude and 48° latitude and 18 km above earth (to avoid atmosphere haze). then I put the ambientlight to the maximum to see the ground even in the night.
Finally I select polaris to look at something else than the ground after the gotolonglat !

Then once the script is finished just press "y" to have a sync orbit with earth and so stay above the same point.

Have fun !

alegator wrote:Is it possible to set in Celestia how the sky will look like at a certain date and FROM A CERTAIN LOCATION (latitude and longitude) on Earth ? (like from a particular city, etc)

Chris posted this method a few weeks ago ( I saved this little bit of text but not the date of his message, which was a bit silly of me ! )

Chris wrote: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.

Then you can use (Y)Sync as Kendrix says.
Or just fly to the place you want to be at, then Sync.
Note that the "arrow" keys on the numeric keypad 4,6,8,2 can also be used to orient your view.

Thanks for the info, I have the following questions:
- Once you run the script, is Celestia able to display North, South, West, East to have idea of the viewing direction?
- My coordinates are 34 south and 58 West, do I have to indicate this with a minus sign before the numbers when using Kendrix's script?
Thanks again.

I recomend buying Starry Night, or some other astronomy software for viewing the sky from earth.
Especially Starry Night Pro is very good.

Celestia is more of a planetarium-software (and a great one at that), while Starry Night is more astronomy, is much more precise, and have much more features.
Tough the prize of Starry Night Pro might seem a "little" steep, its well worth the cash, if you are interested in space and astronomy (as I am).


Alternatively, you may also want to try a freeware program named "Cartes du Ciel".
Its a starmap program for astronomers and skywatchers, which lets you view the sky from your location on planet Earth.
Cartes du Ciel has very few features, however, and I recomend rather buying a real astronomy program instead (and Starry Night simply scores highest among those types of programs, methink).


Stargazer.

"Cartes du Ciel" is excellent...

But the best is "Voyager III" from CarinaSoft...

You can download a demo at http://www.carinasoft.com

It works on a Mac and on Win32 platforms...

(When I had my Amiga I had "Voyager I" it was great !)

Kendrix, Stargazer thanks for the info. I do know that Celestia is not intended to be a skychart and to that end I have Cartes du Ciel.
I would still like to know the following:
- My coordinates are 34 south and 58 West, do I have to indicate this with a minus sign before the numbers when using Kendrix's script?
Thanks.

- My coordinates are 34 south and 58 West, do I have to indicate this with a minus sign before the numbers when using Kendrix's script?

Why don't you use the "Goto Object..." in the menu Navigation (I think you use the windows version) ?
And yes you can use minus sign.

The thing is that, as described in this thread, I don't have it clear how to use the Goto Object command...can you help me?

alegator wrote:The thing is that, as described in this thread, I don't have it clear how to use the Goto Object command...can you help me?

It is not a command, it is in the menu "navigation" and I think quite obvious:

Object Earth
Lat. -34 Long. -58
Distance 0.1 km

I hope this help!
Are you in Buenos Aires or in Uruguay ?

Thanks Calculus, it's clear now. I'm in Buenos Aires. By the way, I checked your website, really nice snapshots of events. I tried replicating the eclipse for Iceland in 2003, I entered the following coordinates for Reijkavik: longitude -21.8 latitude 64.15, and the moon doesn't block the sun at the time you mention, it shows really close though. I tried accelerating time backward and forward and I don't get an eclipse. Could it be because I should use ather coordinates?
Also, shouldn't it be daytime for Iceland at that time (sunrise)? So how do you get a dark lighting in celestia?
Thanks

alegator wrote:Thanks Calculus, it's clear now. I'm in Buenos Aires. By the way, I checked your website, really nice snapshots of events. I tried replicating the eclipse for Iceland in 2003, I entered the following coordinates for Reijkavik: longitude -21.8 latitude 64.15, and the moon doesn't block the sun at the time you mention, it shows really close though. I tried accelerating time backward and forward and I don't get an eclipse. Could it be because I should use ather coordinates?
Also, shouldn't it be daytime for Iceland at that time (sunrise)? So how do you get a dark lighting in celestia?
Thanks

Ola alegator,
I love your city, each time I go there I spend my nights in tango bars!

As for the Iceland eclipse, it occurs during the morning (the sky is not that bright). It is an annular one, so you can still see a ring of fire. And to render it more accurately you have to turn off the atmosphere option. (and don't forget to choose the correct altitude). My coordinate were Lat 64.87349 Long -17.38825

By the way, it's "Hola"....but I understood...happy to know that you enjoy BA, I love this city too (this is where I live). So you come here often? For pleasure or work/study??
By the way, going back to the issu in question, I set the coordinates you gave me and there seems to be an offset in my Celestia because I don't get an overlapping of the lunar and solar disks (they are close though). I checked with aother eclipses (using the "Eclipse Finder" fom the Navigation Menu) and the same happens, no overlapping.
What could it be? As far as my Celestia is concerned I have the latest version and I even added some orbital updates to the ssc file as suggested by
http://www.lns.cornell.edu/~seb/celesti ... index.html

but these do not affect the sun/moon/earth
Any idea as to the possible reason of this?

I suspect this is the atmospheres option. Turn it off.
(I go to BA for business, not pleasure. But I took few days off to visit: Iguazu and Missions)

By the way,
I just posted a new picture of this eclipse, but as seen from the sun.
That makes it easier to understand this unusual eclipse.

Calculus,
sorry for not answering before, I took some vacations. Tell me, what kind of biz do you do in BA?