Celestia Forums

Hi, some questions. I'm using Celestia 1.31p11.

Eclipses: When I use the eclipse finder for finding moon eclipses on earth (moon shadow on earth) Cel. only finds the earth eclipses on moon instead. Can anyone give a hint about that?

Lock function: I read in one of the forum posts that when locking 2 objects like Earth - Mars, Cel should show the distance between these objects. First I find it hard (or maybe I didn't discover the logic yet) to control the lock between 2 objects. Can anyone give a hint about that? Furthermore how can this distance between the 2 be shown.

Goto Surface: I read in one of the forum posts that there in Cel now is an undocumented command CRTL-G for going to surface. I have put my hometown into "Earth-Citys.ssc", and now I move close to earth and use "Select object" type in my hometown and then CRTL-G, and i'm home now. Now I lock "Sync orbit" which also goes fine.
From here my wish is if there was some kind of compass, maybe there is? Can I move around on the earth surface now?
I remember that there was another undocumented function like CRTL-G, wat was this for one?

Best regards
Lars S

LarsS wrote:Eclipses: When I use the eclipse finder for finding moon eclipses on earth (moon shadow on earth) Cel. only finds the earth eclipses on moon instead. Can anyone give a hint about that?

For eclipses by the moon onto the earth, you need to search for "solar" eclipses. While they still involve the moon, everyone calls them solar because it's the sun getting blocked out.

Lock function: I read in one of the forum posts that when locking 2 objects like Earth - Mars, Cel should show the distance between these objects. First I find it hard (or maybe I didn't discover the logic yet) to control the lock between 2 objects. Can anyone give a hint about that? Furthermore how can this distance between the 2 be shown.

Lock is one of my favourite commands... Basically, all you need to do is...
1) Go to the object which you want to be near to you when locked. (For example a spacecraft during an earth flyby etc)
2) Rotate around the first object with the right mouse button until you have the second object (the further away one) within your field of view.
3) Click on the further away object (well, "select" it- there are multiple ways to do it)
4) Press Shift + ;
As long as you don't rotate around the two objects any more, they will both stay locked in the same position on the screen.
To disable this again, just select anything and press f, y etc..

To see how far away you are from the more distant object, (accurately) just make sure you're close to the near object, and then select the more distant one. This way you will get a reading telling you (effectively) how far apart the two are.

From here my wish is if there was some kind of compass, maybe there is? Can I move around on the earth surface now?
I remember that there was another undocumented function like CRTL-G, wat was this for one?

A compass would be pretty nice... Although there is another more roundabout way to find north etc!
Make sure you're looking level or slightly above the horizon, (when on the surface) and press ; This enables the Celestial grid. From looking at this, and the orientation of stars like polaris etc, you should be able to work out *fairly* well, what direction you're pointing.
I agree a compass feature would be good though...
If this isn't quite good enough there are some good star chart programs out there, like Cartes Du Ciel, etc.

You can't actually move around the earth's surface easily, without rotating the planet below you. Or you could input the geographic coordiantes yourself into the GoTo box...

The other undocumented feature you're probably thing of is Ctrl + F, which is AltAzimuth mode. This means that instead of the left/right keys rotating the camera, it actually goes left & righ, like with an altazimuth telescope mount etc.

Hi Jack, thanks for some very good answers

Regards Lars