Eccentric Orbits

Telakin · Jan 21, 2016

During the news of a possible ninth planet in our solar system (http://news.nationalgeographic.com/2016/01/150119-new-ninth-planet-solar-system-space/) I came across a diagramm of objects already identified that do not have the single plane orbits of the major planets.

See here: https://en.wikipedia.org/wiki/2013_BL76#Comparison

Are such orbits already in game, could they be, will they be? I do find the standard planar orbits rather monotonous during exploration.

paulca · Jan 21, 2016

Telakin said:
Are such orbits already in game, could they be, will they be? I do find the standard planar orbits rather monotonous during exploration.

There are two different parameters here.

Eccentricity is the ratio between the periapsis and the apoapsis (perogee, apogee). A circular orbit will be 0.0. https://en.wikipedia.org/wiki/Orbital_eccentricity (EDIT: This link highlights how simplistic my description is, as not all orbits have apogees)

Relative inclination. The planar angle relative to a reference plane. In the case of a solar system that can be the mean plane of the orbits, the galactic plane or the sol reference plane, the plane of the ecliptic. https://en.wikipedia.org/wiki/Ecliptic

I have seen fairly high relative inclination in ED, not sure about highly eccentric. The thing about highly eccentric orbits is they tend not to play well with others. In our solar system the highly eccentric orbits are limited to roaming asteroids and comets. Anything large on a highly eccentric orbits caused someone a bad day long ago, they would be guaranteed to cause chaos to other bodies orbits and destroy the solar system or themselves. So anything in ED's simulated galaxy which has a highly eccentric orbit would be very small, comets, asteroids, etc.

Sapyx · Jan 21, 2016

There are many planets in the ED universe which are on eccentric orbits and/or have out-of-ecliptic-plane inclinations. I've frequently spotted "rogue planets" - moonless gas giants or large heavy-metal-content planets, much further out from the star than the rest of the planets in the system and in highly eccentric, "comet-like" orbits. Next time I spot one out here in the black, I'll try to remember to take a picture and post it here.

If you fly with orbit lines on, you can detect the existence of non-planar planets very easily. Eccentricity is harder to detect, because you aren't given the Eccentricity statistic until after you've scanned the planet.

Sapyx · Jan 21, 2016

Oh, my second-to-next planetary system I jump into after I made that post has a mildly eccentric orbit. I'll do for starters.

There's only one planet in the system, so it doesn't illustrate inclination variablility. And it's an iceball rather than a HMC or gas giant.

This is an almost perfectly top-down view of the system. The system's sun is at one focus of the ellipse.

And here's how it looks on the system map. The reported eccentricity is "0.4052" and still looks kind of circular. I'm pretty sure I've noticed eccentricities over 0.7 in the game. By comparison, Sedna's orbit has an eccentricity of 0.8549 ad Halley's Comet an eccentricity of 0.967.

Telakin · Jan 21, 2016

Thanks both for the interesting feedback. I guess it is worth looking at the figures a bit better and not to succumb to being a honk-and-jump explorer ...

Sapyx · Jan 22, 2016

OK, I found an even more eccentric rogue planet. This one's a gas giant, a water-life-bearing one at that. Here's the top-down orbital view; the sun it is orbiting is the brighter of the two central stars, the other is just a background star:

And here's the system map info on this planet. Eccentricity statistic: 0.8969, definitely in the "cometary" class of eccentricity. The poor little lifeforms must get toasted by solar radiation in the brief but intense summer. Also see that the "Inclination" is at 74 degrees; this is presumably in relation to it's star's equator, since there aren't any other planets in the system to form an "orbital plane" to compare it with.

ratchet5000 · Jan 22, 2016

Sapyx said:
OK, I found an even more eccentric rogue planet. This one's a gas giant, a water-life-bearing one at that. Here's the top-down orbital view; the sun it is orbiting is the brighter of the two central stars, the other is just a background star:
View attachment 97207

And here's the system map info on this planet. Eccentricity statistic: 0.8969, definitely in the "cometary" class of eccentricity. The poor little lifeforms must get toasted by solar radiation in the brief but intense summer. Also see that the "Inclination" is at 74 degrees; this is presumably in relation to it's star's equator, since there aren't any other planets in the system to form an "orbital plane" to compare it with.

View attachment 97206

They could just hibernate like a wood frog during the coldest leg of their "year", and come back to life during the orbit's perihelion.

Colonel Kenney · Jan 22, 2016

Been complaining about that and the stellar forge for a long time.

You also don't really see any crossing orbits because they don't want collisions to happen and are not sure how to handle any gravitational effects that may happen.

This really doesn't simulate gravity except for planetary landings.

You'll see with binary stars and some larger things but thats it.

Sapyx · Jan 23, 2016

And now, let's look at the other aspect - radical inclinations from the rest of a solar system.

Here's a really hoopy planet I just spotted. It's a huge Ammonia World with 3 moons, yet has "no atmosphere" - so if you've ever wondered what a Thargoidesque planet looked like without all that pesky haze and clouds in the way, here it is. Still can't land on it, though - Water Worlds and Ammonia Worlds are currently off-limits, even if they're officially atmosphere-less.

Eccentricity for this one is 0.09 - barely out of circular (by comparison, it's about the same eccentricity as the orbit of Mars). But the Inclination is at -60 degrees, which is easily noticeable while supercruising around int he inner system. Unfortunately, orbital lines aren't visible when you're too far away unless you've got the planet in question selected, so we'll have to make do with these two side-by-side shots, taken from an oblique angle to the system plane. The first has the second-last planet highlighted; the second has the rogue ammonia world highlighted.