Kerbal Astronomy

[55delta]

I recall someone once in an old KSP-TV stream had once made a sextant to use with looking out a capsule window and get a reading on the stars in space. Has anyone else ever tried this? By extension, is it possible to navigate in KSP using the stars in stock KSP? Like writing up a star table, for example, to tell you where you should be if you can see certain stars at certain angles.

Also, outside of just extracting the sky-box outright, has anyone made a star chart for KSP? I'm rather curious to know.

Edited February 3, 2018 by 55delta
Changed title

[Spricigo]

7 hours ago, 55delta said:

..., outside of just extracting the sky-box outright, ...

If that is possible, why bother with a less precise alternative?

[Just Jim]

8 hours ago, 55delta said:

I recall someone once in an old KSP-TV stream had once made a sextant to use with looking out a capsule window and get a reading on the stars in space. Has anyone else ever tried this? By extension, is it possible to navigate in KSP using the stars in stock KSP? Like writing up a star table, for example, to tell you where you should be if you can see certain stars at certain angles.

Also, outside of just extracting the sky-box outright, has anyone made a star chart for KSP? I'm rather curious to know.

I toyed with the idea of making Kerbal Constellations for Emiko, but then I switched to a custom skybox, which wouldn't work for everyone, obviously.

But I would love to see someone(s) take a shot at it, if they were interested. If you had half a dozen, or more, recognizable groupings, or constellations, it might be possible to get yourself orientated using just the stars...

And all I ask is a tall (rocket-powered) ship and a star to steer her by... 

 

[The Aziz]

Well.. Technically, skybox is a skybox. Set yourself in orbit close to the sun or near Eeloo, and stars will be in the same positions.

Taking the technicalities aside. Within one solar system the stars we see most likely won't change their positions that much, we're talking about distances measured in lightyears.

Also, I have no idea how sextant works, but I believe there are two things needed besides the sky. Time, and static point of reference, which in most cases is the sea. You can't really tell where you are when you don't know at what angle from the horizon was that star at the same time yesterday.

[55delta]

For sextants at sea, I recall it as you put the star you want in the the mirror half of the scope, the adjusted the sextant so star in the mirror is level with the horizon. Then you read off the angle on the sextant, and repeated the process with a second star. Then you check the time, then looked up the stars in the table to figure out where you are based on seeing both stars at that time, at that angle. I'd have to look up what was needed for navigating in space. 

Still, I thought there was an old constellation thread around here somewhere. Not to mention the question of whether a skybox can give reliable readings. I don't recall if the skybox is fixed to the Kerbol system or the active vessel\camera.

Edited February 1, 2018 by 55delta

[linuxgurugamer]

Skybox isfixed to the system.

That being said, it would be an interesting exercise, but not really useful.

 

[Aegolius13]

5 hours ago, The Aziz said:

we're talking about distances measured in lightyears.

Or parsecs - since this is where the unit parsec* came from: how much parallax, or apparent movement, a star displays based on where the earth is in its orbit around the sun.  

 

*at least in the non-Kessel Run context.  

[The_Rocketeer]

Celestial navigation fascinates me as a concept, but I lack the range and freedom on planet Earth to be able to practice it much. A mod or guide to be able to do this in KSP would be something I would welcome.

Edited February 1, 2018 by The_Rocketeer

[Archgeek]

While a sextant would work alright down on Kerbin (or any of the airless world + Lathe's surfaces), provided you had a chart for each world (different diameters yield different angles), it'd be pretty useless up in space, due to the lack of a horizon, and the whole reason they work planetside being the stars' relative lack of motion.

You can use the stars to orient in space, though, and lots of real-life space probes use it all the time.  Just find a constellation, and you know what direction you're looking relative to the sun.  You can also use the location of the sun relative to the constellations to find your angular position in the system, and the sun's apparent brightness to gauge your distance from it, giving you all the information you need to find your position relative to it.  If you can get two different measurements, you can even combine the apparent motion of the sun with your position and distance to find your velocity vector, and thus your current orbit.

[55delta]

I will agree that, in a game with a map mode and KerbNet, that it would be more a curiosity than anything else. But so far it does sound like Kerbol astronomy is...uncharted territory.

I might consider trying to work out some sort of sky chart or such. However, usually the closest I get to astronomy in RL is staring at the moon. So I would have to do a bunch of research first. Not to mention practicing my amateur MS paint skills and other things. 

 

[luizopiloto]

The Skybox can be used for navigation... I still remember an astronomer that plays KSP did some research and found a bug in the game... because sideral time and solar time back there was different from the intended... He used the stars as reference...a and did all the calculations...

[55delta]

Sounds like it's possible that someone has done stuff, but it's not on the forums or wiki.

Anyway, the view from KSC is, I'm guessing, 3 and 1/2 hours of the space skybox with at least three magnitude-1 stars in likely separate constellations. I'm guessing at magnitude as I don't have a gauge for that. Fortunately, KSC is on the equator, so compass directions are very simple. However, I expect that the skybox is deceptive and Kerbin is not as squarely on the galactic plane as it appears.

Edited February 2, 2018 by 55delta
I don't know how to re-title a thread

[55delta]

So I did a bit of research and I decided I want to make a star catalog. It's going to be a bit of a project. I was thinking I'd call it (I like to give stuff code names) Project Ptolemy. Although it makes me think I should call the catalog the Kalmagest, because the accuracy might be subject to debate.  Still, could be subject to change if everyone can agree on a superior name.

The good news is that I only have a set amount of stars to classify (unless they change the skybox in an update.) But I'm going to have to figure out how to classify each star, as there's no agreed constellations yet and I have to define a reasonably common relative position. I'll have to work on that. Then there's the stars themselves, as I don't yet have a magnitude gage, sextant, or compass\protractor on hand. It'll be difficult and mostly pointless, so should be fun.

[55delta]

I did make a bit of progress. I found a copy of KSP's default skybox. That should help me find the stars.

I still need to research how to classify stars. Ideally, I want to do it the way RL astronomers do, to make the chart easier for general use. Also, although there are a few ways to build a sextant, I need both the scope and mirror. I won't be able to definitively stand on level ground, so I'll need to use the in-game horizon.

[55delta]

I've been doing research. So, the Yale Bright Star Catalogue recognizes star of celestial magitude of 6.5 and brighter, which is the closest in comparison to what I'm looking to do. I doubt there's any stars in the sky dimmer than that.

A bit of advice, skip checking star catalogs and just look up 'star position' in Wikipedia if you want to know how the position of stars is determined. So position is determined by declination to the celestial equator and right ascension. 

KSP will be easier than RL astronomy in a few ways. The celestial sphere (skybox) only moves as a whole, as opposed to RL star proper motion. Kerbin's equator, celestial equator, and galactic plane are pretty much the same. Also, Kerbin's poles can't move, so it doesn't have precession (so no need for epochs).

I'm thinking that at some point I should work out the measurements and trigonometry to take some measurement to figure out how 'far' away the stars are. I'm not a math major, wish me luck.

[klesh]

I try not to look at the skybox very much.  Its very 2011. 

[55delta]

On ‎2018‎-‎02‎-‎09 at 8:34 PM, klesh said:

I try not to look at the skybox very much.  Its very 2011. 

And you would do in-game astronomy with a different skybox?

Continuing the project, I have a bit of a problem with right ascension. Seeing as there's no March Equinox, I'm still trying to work out as starting point to measure from. Aside from where the texture ends and starts (which is deliberately not noticeable), I kind of have to select something notable and agreeable as 'start timing here' by the few who're interested. Right ascension, as opposed to sidereal, is measured in time.

For the very few who want to fiddle around with this sort of thing, you can find copies of parts and the whole of the skybox from the website of TheReadPanda, under games and Constellations of KSP. The project itself only had one video about a year ago, but the files are still there for download.

I'd also like to take a moment to thank Twitch streamer TheReadPanda, for providing the files and being an entertaining red panda.

Edited February 11, 2018 by 55delta

[Annadog40]

TheReedPanda has a second video where they show some constellations already made.

 

 

 

This is quite interesting, I spend hours in stellerium looking at the constellations and how they are different on different planets and dwarf planets and will be very curious on what the constellations are.  (Also I wonder if Kerbian Astrology could take place :P)

 

I was looking around and I think this thread might help

 

Edited February 28, 2018 by Annadog40