View Issue Details
| ID | Project | Category | View Status | Date Submitted | Last Update |
|---|---|---|---|---|---|
| 0001358 | SkyChart | 1-Software | public | 14-08-19 11:27 | 17-10-21 20:28 |
| Reporter | James Dietrich | Assigned To | Patrick Chevalley | ||
| Priority | normal | Severity | feature | Reproducibility | have not tried |
| Status | assigned | Resolution | open | ||
| Target Version | 4.4 | ||||
| Summary | 0001358: show orbits of planetary satellites | ||||
| Description | From https://groups.yahoo.com/neo/groups/skychart-discussion/conversations/messages/8571 ---------------------- I'm having a difficult time figuring out how to make a path for a planetary moon. I've got the object visible on the screen near the planet and the simulator box is set, but there appears to be no way to select an individual moon. I can get a path of Saturn in the sky, but I'm looking to create the orbit of Iapetus around Saturn with tick marks for dates. I would be so grateful for help in this. ---------------------- I think this would be a useful feature for Skychart to have. This doesn't seem like it would be simply an extension of the current simulation mode. Rather, it's really an option to show the satellite's orbit. Near the bottom of this page is an example of such a map being used: http://www.skyandtelescope.com/astronomy-news/observing-news/saturns-moon-iapetus-comes-bright-side/ And this link has a similar chart to be used for locating Neptune's moon Triton: http://observing.skyhound.com/shallow_sky/neptune.html (It wouldn't make any sense to show the stars or other bodies (asteroids, etc) in such a diagram, because their position would only be accurate for one moment in time, and the satellite diagram will likely show days or weeks of time. And there's already a good way to see the current position of the satellite with respect to its planet and the stars.) Below are several ideas I have on implementation, to help start the discussion on that: Some thought should be given how to handle multiple satellites around one parent planet. I think it would easily get too cluttered and confusing to show dates on more than one satellite's orbit. So it might be best to show dates on just one satellite's orbit. It could be very helpful, though, to show one or more other satellites' orbits just for visual reference, but not have dates labeled on them. So one would need to be able to choose, for each satellite, whether to show its orbit, and also which satellite should be labeled with dates. Another consideration is the time span of the diagram. If only one satellite can be labeled with dates, then the most natural time span for the diagram is one revolution of that satellite around its parent planet. Of course the start time would need to be specified somehow. Also related is deciding how frequently to display the labels. Probably something like the current simulation mode would work for this. Show tick marks at a certain interval, and print labels on every one, or every other one, or every fourth one, or just the first and last, etc. | ||||
| Tags | No tags attached. | ||||
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I agree with your remarks. This can be implemented with a new entry in the right click menu when the pointer is over a planet or a satellite. This open a selection window with the list of all the satellites for this planet. From the list you can select which one you want the orbit and the labels. At the bottom there is a few option for the labels. For me the most natural start date is the current date of the map. Each satellite orbit and label are show for a single complete revolution. So the end date is not the same for all the satellites. The orbit orientation in space and the axis scale is show for the start date and every orbit point is show with the same orientation to allow the orbit to close at the end point. This is an acceptable approximation and make the drawing more easy to understand. |
| Date Modified | Username | Field | Change |
|---|---|---|---|
| 14-08-19 11:27 | James Dietrich | New Issue | |
| 14-08-20 11:44 | Patrick Chevalley | Note Added: 0002920 | |
| 14-08-20 11:44 | Patrick Chevalley | Assigned To | => Patrick Chevalley |
| 14-08-20 11:44 | Patrick Chevalley | Status | new => assigned |
| 14-08-20 11:44 | Patrick Chevalley | Target Version | 0.3.0 => 4.0 |
| 15-04-01 10:56 | Patrick Chevalley | Target Version | 4.0 => 4.2 |
| 17-10-21 20:28 | Patrick Chevalley | Target Version | 4.2 => 4.4 |
