Newcomer / Intro Do the planets and other things move in ED?

[_bryan]

Hi folks,

I was just wondering, do the planets move around the stars? If so, do the planets "pull" on each other with their own gravity?

I believe I have flown to the same stations many times and the station is in a different place, so it feels like the stations move around.

Also, when I'm approaching a station in SC, sometimes it seems to "move around" at the last second. Is that something to do with it moving in its orbit?

Thanks.

V/r,
Bryan

 

[Old Duck]

Yes, this is one of the things that makes Elite great and unique - realistic satellite motion (rotation and revolution). You can even catch solar eclipses if you're down on a planet in the right place at the right time!

 

[metatheurgist]

Go to Epsilon Indi and check out what's around New Africa.

 

[Skürt Avil]

Check out Miterand's Hollow

 

[Skürt Avil]

A few months ago, there was an incident where two Gas Giants intersected. Can't remember the name of the system though.

 

[Alec Turner]

Here's a timelapse sunset over a crater ..

Source: https://youtu.be/uX3vEJ5l2B8

If you're in the right place at the right time you can also see shadows creeping across the ground during a sunset/sunrise and then follow the shadow's edge.

Source: https://youtu.be/eyMTSFAzo64


n.b. I suspect this is broken in Odyssey as I haven't (yet) observed any light/shade effects nearly as refined as these in that version of the game.

 

[Sapyx]

Do planets move around stars? Yes. And moons and space stations move around planets, and stars move around each other if they're in the same system.

Do planets interact with each other? For the most part, no. The "n-Body problem" is unsolvable by our best supercomputers, and leads to chaotic solutions that could not be reliably and repeatedly calculated via procedural generation, so in ED, gravity is simplified to a series of nested two-body problems. Thus, two planets in separate orbits around a star will not interact with each other. If theyr'e close enough, they can even "collide" with each other, though it's more "passing through each other" than an actual planetary collision. However, you can have two planets co-orbiting each other, with the barycentre of those two planets then in orbit around the star.

This simplified gravitational formula can, however, still create some interesting and realistic dynamics. Planets can be found in Trojan orbits of gas giants, for example.

MItterand Hollow, a small moon orbiting the planet New Africa in the Epsilon Indi systm, is an anomaly. Epsilon Indi is a hand-coded (not procedurally-generated) system, with data copied aross from the prequel Elite games. Whoever did the copying made an error, and accidentally gave Mitterand Hollow a super-short orbital period (86 seconds). It's a bug, which FD have chosen not to fix. This moon orbits this planet at unrealistic speeds; it's so fast that it's impossible to catch it in Supercruise. You have to park your ship in the moon's orbital path, and let the moon slam into you.

 

[_bryan]

I think I noticed something while I was exploring. If I stop and come back the next day, all the stars moved. But in reality I think my system is what's moving and my ship is "stopped" in my system so technically I'm moving. Or something like that.

Something that has confused me about the "fake physics". How does the ship know how fast it's going?

 

[Sapyx]

I think I noticed something while I was exploring. If I stop and come back the next day, all the stars moved. But in reality I think my system is what's moving and my ship is "stopped" in my system so technically I'm moving. Or something like that.

That's another thing that's "unrealistic" about the ED galaxy: star systems don't move. The stars on the galaxy map (representing star systems) are at fixed co-ordinates and are locked in place. So what you're seeing isn't "systems moving". You might be noticing that your plotted route is changing; that's because the route plotter doesn't use an absolute "best possible route" (again, this would be computationally too time-consuming), it just calculates a "best route it can figure out in a few seconds". Which will change if you move to another star system along the route and ask it to calculate again.

Something that has confused me about the "fake physics". How does the ship know how fast it's going?

Ship speeds are calculated relative to the object that's considered the local Zone of Control. Remember how I said earlier that gravity is simplified and only a single object is considered to be having a gravitational pull at any given point in space? Those objects have "Zones of Control", within which they are the gravitational source and point of reference for speed calculations. There are sharp (invisible) boundaries between these zones. You can tell which object's zone you are in by the name in the bottom left corner of the screen.

Example: you arrive in the system, and you're in the Zone of Control of the primary star. Move away from the star towards a planet and the name might change to "shipping lane" or "deep space", but that's still within the Zone of Control of the star (the different names here are just indicators of changing probability of NPCs - pirates, police patrols, etc). But get close enough to the planet, and the name in the bottom left corner will switch to the planet name. Get within 1000 km of a space station, and the Zone switches to the space station.

Bigger (heavier) planets have bigger zones of control. A moon's Zone of Control will usually be completely embedded inside the Zone of control of its parent planet.

You can see the effect this has on speed calculations at Mitterand Hollow. If you approach and fly around New Africa, New Africa will be your Zone of Control. But if you park (Supercruise idling speed of 30 km/s) in the path of Mitterand Hollow, the moon's Zone of Control will eventually "hit" you, and you will be swept up by the moon's Zone of Control; your speed will now become 30 km/s relative to the moon, not the planet - which is several thousand km/s relative to the planet.

If you are paying attention (external camera) when this happens, you will notice your ship's thrusters suddenly firing up at the transition point; they are trying to attain the new, sudden velocity change asked of them.

 

[_bryan]

That's another thing that's "unrealistic" about the ED galaxy: star systems don't move. The stars on the galaxy map (representing star systems) are at fixed co-ordinates and are locked in place. So what you're seeing isn't "systems moving". You might be noticing that your plotted route is changing; that's because the route plotter doesn't use an absolute "best possible route" (again, this would be computationally too time-consuming), it just calculates a "best route it can figure out in a few seconds". Which will change if you move to another star system along the route and ask it to calculate again.


Ship speeds are calculated relative to the object that's considered the local Zone of Control. Remember how I said earlier that gravity is simplified and only a single object is considered to be having a gravitational pull at any given point in space? Those objects have "Zones of Control", within which they are the gravitational source and point of reference for speed calculations. There are sharp (invisible) boundaries between these zones. You can tell which object's zone you are in by the name in the bottom left corner of the screen.

Example: you arrive in the system, and you're in the Zone of Control of the primary star. Move away from the star towards a planet and the name might change to "shipping lane" or "deep space", but that's still within the Zone of Control of the star (the different names here are just indicators of changing probability of NPCs - pirates, police patrols, etc). But get close enough to the planet, and the name in the bottom left corner will switch to the planet name. Get within 1000 km of a space station, and the Zone switches to the space station.

Bigger (heavier) planets have bigger zones of control. A moon's Zone of Control will usually be completely embedded inside the Zone of control of its parent planet.

You can see the effect this has on speed calculations at Mitterand Hollow. If you approach and fly around New Africa, New Africa will be your Zone of Control. But if you park (Supercruise idling speed of 30 km/s) in the path of Mitterand Hollow, the moon's Zone of Control will eventually "hit" you, and you will be swept up by the moon's Zone of Control; your speed will now become 30 km/s relative to the moon, not the planet - which is several thousand km/s relative to the planet.

If you are paying attention (external camera) when this happens, you will notice your ship's thrusters suddenly firing up at the transition point; they are trying to attain the new, sudden velocity change asked of them.

I'm going to have to read this a couple times to understand better. BUT I do think you're right---it was the different plot, not the system.

Re: the New Africa thing. Is that why when I'm approaching a place like Robigo Mines, that it keeps moving to the right at the very end?

 

[JetsonRING]

Hi folks,

I was just wondering, do the planets move around the stars? If so, do the planets "pull" on each other with their own gravity?

I believe I have flown to the same stations many times and the station is in a different place, so it feels like the stations move around.

Also, when I'm approaching a station in SC, sometimes it seems to "move around" at the last second. Is that something to do with it moving in its orbit?

Thanks.

V/r,
Bryan

Go to Mitterand Hollow and find out. o7

 

[Ashnak]

Re: the New Africa thing. Is that why when I'm approaching a place like Robigo Mines, that it keeps moving to the right at the very end?

The station (or moon) is always moving - it's just that this (in most cases - c.f. Mitterand Hollow) usually only becomes apparent when you're close enough, but still outside the local sphere of influence. M.H. is the most extreme example, but I've encountered more than one body/station that were hard to catch.

 

[Sapyx]

Is that why when I'm approaching a place like Robigo Mines, that it keeps moving to the right at the very end?

More or less, yes. Robigo Mines orbits close by a gas giant. Orbital speeds of objects orbiting gas giants are typically much higher than for similar objects orbiting a smaller terrestrial planet. So once you get close, you will find the target "drifts" along in its orbit, trying to get away from you.

 

[Esteban]

Today I accepted a hit mission where I had to scan a datalink to find the location of the target. The installation where the datalink is located is one Barcelo Penal Colony+ on a body named Mitterand Hollow.

I said to myself: that name is familiar. It's the same as that thread in the exploration forum about one very fast-moving moon, but that's out in some system far away!
I was incorrect! it is the same one (in the Epsilon Indi System) that's being discussed in that thread.

I had a lot of fun as I approached and realized that this moon is traveling so fast. It's very easy to put yourself into the orbit line of this body (even if you don't have orbit-lines showing) and to get yourself 'locked' into orbit and eventually land on the moon.

What fun!

Spoiler: Fast mover!

...especially to happen upon this without doing so intentionally. Fly adventurously, CMDRs!

(in EDH)

 

[Old Duck]

That's another thing that's "unrealistic" about the ED galaxy: star systems don't move. The stars on the galaxy map (representing star systems) are at fixed co-ordinates and are locked in place.

It would get really squirrelly to try to model galatic star motion and position accurately, because stars aren't where they appear to be; stars appear where they were, not where they are (assuming said stars "are" in present day). If you see a star 1000 LY away, you're seeing that star 1000 years ago. It would naturally change in perceived position as you get closer, and perhaps size and color. Then take nebula - they should expand as you get closer, assuming their gasses are still flying away from the supernova(s) that created them.

Of course you know this, because you're a very clever fellow based on what I've read from your posts.

 

[Sapyx]

It would get really squirrelly to try to model galatic star motion and position accurately, because stars aren't where they appear to be; stars appear where they were, not where they are (assuming said stars "are" in present day). If you see a star 1000 LY away, you're seeing that star 1000 years ago. It would naturally change in perceived position as you get closer, and perhaps size and color. Then take nebula - they should expand as you get closer, assuming their gasses are still flying away from the supernova(s) that created them.

True; the speed of light being effectively infinite is just another "simplification" the game requires.

For many of the things discussed in this thread, the main reason they aren't in the game is that, for 99% of the time, most players wouldn't even notice if they were in the game or not. It'd take a lot of work, and a lot of background computation requirements, for something that might impress a handful of physics and astronomy fanatics but would literally make no difference to the gameplay of most players, most of the time.

Even the simplified-Newtonian orbital motion that the game does implement (which was the origin of this thread) is hardly ever noticed by the vast majority of players most of the time. It really only rears its head when a space station happens to move behind its planet in its orbit, and a player has to spend an extra few seconds avoiding the planet while on final approach that they didn't need to do the last time they were in that system. Or maybe while in the middle of Supercruising across a system, an intervening planet that used to cause a Supercruise slowdown a few months ago has moved along in its orbit and is no longer in the way.

 

[Old Duck]

Even the simplified-Newtonian orbital motion that the game does implement (which was the origin of this thread) is hardly ever noticed by the vast majority of players most of the time. It really only rears its head when a space station happens to move behind its planet in its orbit, and a player has to spend an extra few seconds avoiding the planet while on final approach that they didn't need to do the last time they were in that system. Or maybe while in the middle of Supercruising across a system, an intervening planet that used to cause a Supercruise slowdown a few months ago has moved along in its orbit and is no longer in the way.

I notice it all the more by by its absence in other games. For example, when I build a base or space station in Space Engineers or No Man's Sky, I instinctively expect to see planet (or moon) fall and rise, along with the stars moving across the sky. But I don't, because everything is static except the sun, which is literally drawn by Apollo's Chariot across the sky. This is one of my biggest disappointments in these other games, and it's why I appreciate Elite's more accurate planetary motion all the more.

The irony is that Elite really doesn't do anything to entice people to stay in one place long enough to truly appreciate the changes in moon phases, planet alignment and seasons - in fact, it actively encourages people to be on the move unless they really want to pick a base of operations at a single station / planetary outpost for weeks and even months.