Celestia Forums

I may need some help here; I've re-installed Celestia and deleted its .plist (OS X) to no avail.

I've gotten used to going to a planet, then right-clicking to Lock Phase so I can watch the texture spin underneath a consistent coverage of sunlight. Earlier, I had a planet in Lock Phase, and zoomed way out, speeding up time so that I could actually see the Local Group and then eventually the Milky Way spin, from the outside. This worked fine..

I sped up to a point where the Milky Way actually flipped over. Intrigued, I let those go by several times. Then I zoomed back in to my anchoring planet.

The problem was, the planet was not Tidally Locked, whether I viewed it via Lock Phase or some other setting. I couldn't correct it no matter what I did, and eventually re-installed.

Now, when I start out in the Solar System, the planets rotate properly... but when I view an exoplanet and travel there, sometimes it spins properly and sometimes it is Tidally Locked.

Has anyone ever heard of anything like this before?

Guess this is what I get for giving the Milky Way a spin...


- Heath

Which version of Celestia are you running?
v1.4.1?
a v1.5.0 prerelease?

Can you provide a precise prescription for demonstrating the problem?
e.g.
goto <planet name>
type colon
goto ...

Unfortunately, English phrases describing what to do can be ambiguous, making it difficult to be sure one has followed the correct procedure for reproducing the problem.

p.s. some exoplanets are tidally locked and some are not, depending on their orbits.
Which ones do you look at that sometimes are locked and sometimes not?

p.p.s.

Part of my confusion is because I see no "phase lock" option in the right-mouse-button-popup menu, although there is a "sync orbit" option.

I'm using Celestia v1.5.0 pre2 under Windows.

Also, there is no planet in the solar system that's tidally locked, so you'll need to be specific about where you start.

Hard to say if the actual steps would replicate the problem, since I still have the problem and therefore can't re-break it. I could list the steps (if I remembered them precisely), but could not know if they would result again in the problem I still have. Nevertheless:, this following for me results in viewing a planet which is not meant to be Tidally Locked (from other times I've viewed it), which now is:

Launch
Rt-click Earth; Lock Phase
Increase time by 5 steps (L L L L L)
Zoom out by 23 orders of magnitude (assuming that a single backwards wheel-scroll is one order of magnitude)
Increase time by 5 more steps (L L L L L)
Watch the Milky Way whirl until year 8000.
Target Name: RHO1 Cnc
Go to selection (G)
Slow down by 7 steps to avoid nausea (K K K K K K K)
Pointer-select planet 'b'
Go to selection (G)

It should still be Lock Phase viewed, and it should appear Tidally Locked.

That's the best I can do.

- Heath

The definition of RHO1 Cnc b in Celestia/data/exoplanets.ssc does not specify any rotational parameters. When there are no rotational or orientation parameters specified for a body, Celestia is supposed to show that body tidally locked to its primary. That particular exoplanet is being shown correctly tidally locked on my system.

For me, G always has set the viewing coordinate system to be "Follow." "Phase Lock" is lost immediately when G is typed. It switched to "Follow" when I typed a G as in your instructions and did not continue to be phase locked.

As I mentioned, there is no "Phase Lock" option in the rmb menu of the Windows version of Celestia. I suspect that there is a bug in how its implemented in the Mac version.

Well, at least it wasn't because of what I did, I guess. And I can usually piddle around to get a body to rotate it seems. Thanks for taking a look.

- Heath