The problem has been identified and is also a known issue that I was able to find after the circumstances that caused the bug to appear were demonstrated. This is a link to the issue: github.com/Stellarium/stellarium/issues/391
I can't use sound right now so don't know what the alien is saying, but may be worth trying the #stellarium IRC channel or forum, e.g. answers.launchpad.net/stellarium ?
I think you're just seeing a combination of libration plus the viewpoint lock to a distant star. If you lock viewpoint to the moon and zoom in you'll see the visual effects of libration match the speed up and slow down.
RayFranklin I’ve played around with it more since the video but haven’t corrected it yet. Libration doesn’t make sense to me because the period of the oscillation is one day. I have tried locking to Polaris that didn’t help. I’ll try locking to the moon next as you suggested.
@@allgreymatters9341 Remember Stellarium is rendering the sky from an Earth-based viewpoint. Diurnal libration is viewable every 24 hours as the moon passes over you since you're viewing it from one side of the rotation to the other side. It's a smaller effect than the longitudinal or latitudinal libration but might account for the effect seen in Stellarium. Actually I believe longitudinal libration oscillates daily as well. Only latitudinal has a period that coincides with the lunar month.
@@rayfranklin7646 Shouldn't it go away if I use the north pole as my viewing location then? I was playing with it more a little while ago, when I lock on the moon and view from the north pole I get an identical phenomena.
@@allgreymatters9341 Hmm, that would get rid of the diurnal libration I would think, yeah. I just reloaded the program and watched through a full sidereal month and noticed the apparent velocity of the moon varies so it could also just be showing the change in orbital velocity from perigee to apogee. The same pattern would be apparent if you charted the lunar version of an analemma.
Interesting... Might the fact that the moon doesn't orbit the earth play a role there ? Because earth and moon orbit around the combined center of mass of the earth-moon system.
@@allgreymatters9341, hmm, but the modelling software has Kepler's laws built into it, right ? So it comes up with that simulation based on those. And the moon shows a periodic change in velocity relative to the background ?
ToyFabrik shouldn’t the velocity increase only during the portion of the orbit that the moon is approaching earth, twice in the monthly orbit? The timing in the video has the wobble twice a day or so if memory serves.
![[UNCUT] "บอสณวัฒน์" แฉ! แหล่งซุกเงินแก๊งบอส ขยันผิดที่ไม่กี่ปีก็เข้าคุก l คนดังนั่งเคลียร์ l17ต.ค.67](http://i.ytimg.com/vi/BL56qIfXYZM/mqdefault.jpg)
The problem has been identified and is also a known issue that I was able to find after the circumstances that caused the bug to appear were demonstrated.
This is a link to the issue: github.com/Stellarium/stellarium/issues/391
I can't use sound right now so don't know what the alien is saying, but may be worth trying the #stellarium IRC channel or forum, e.g. answers.launchpad.net/stellarium ?
I think you're just seeing a combination of libration plus the viewpoint lock to a distant star. If you lock viewpoint to the moon and zoom in you'll see the visual effects of libration match the speed up and slow down.
RayFranklin I’ve played around with it more since the video but haven’t corrected it yet. Libration doesn’t make sense to me because the period of the oscillation is one day. I have tried locking to Polaris that didn’t help. I’ll try locking to the moon next as you suggested.
@@allgreymatters9341 Remember Stellarium is rendering the sky from an Earth-based viewpoint. Diurnal libration is viewable every 24 hours as the moon passes over you since you're viewing it from one side of the rotation to the other side. It's a smaller effect than the longitudinal or latitudinal libration but might account for the effect seen in Stellarium.
Actually I believe longitudinal libration oscillates daily as well. Only latitudinal has a period that coincides with the lunar month.
@@rayfranklin7646 Shouldn't it go away if I use the north pole as my viewing location then? I was playing with it more a little while ago, when I lock on the moon and view from the north pole I get an identical phenomena.
@@allgreymatters9341 Hmm, that would get rid of the diurnal libration I would think, yeah. I just reloaded the program and watched through a full sidereal month and noticed the apparent velocity of the moon varies so it could also just be showing the change in orbital velocity from perigee to apogee. The same pattern would be apparent if you charted the lunar version of an analemma.
@@rayfranklin7646 I swear the interface for stellarium changed since this morning. Or maybe I am going nuts. Both are conceivable lol.
Interesting...
Might the fact that the moon doesn't orbit the earth play a role there ? Because earth and moon orbit around the combined center of mass of the earth-moon system.
ToyFabrik that was one of the possibilities I was kicking around but I’m not sure how to confirm it. Also, the period seems fast for that.
@@allgreymatters9341, hmm, but the modelling software has Kepler's laws built into it, right ? So it comes up with that simulation based on those. And the moon shows a periodic change in velocity relative to the background ?
Isn't that exactly Kepler 2 in action ? Conservation of angular momentum ?
Okay, so the effect seems to be a 24h rhythm, as far as i can tell from your video
ToyFabrik shouldn’t the velocity increase only during the portion of the orbit that the moon is approaching earth, twice in the monthly orbit? The timing in the video has the wobble twice a day or so if memory serves.