Celestia Forums

Hi folks...

I'm beginning to sketch out my entry for the Toliman (Alpha Centauri B) System, and thought I'd run them by you. Once I get a generalized idea of what I want, I'll start on the ssc file(s).

PLANET I: Baahki is a lower-massed world kept geologically active by the massive tidal stretching produced by its large (approximately half the diameter of Baahki itself), volcanically active moon. The second and smaller moon, while further out, also adds something to this effect. While the planet has no tectonic plates, volcanic activity and erosion slowly changes the surface over tens of millions of years.

PLANET II: Eutresca is a smaller, rocky world, heavity cratered. It is similar to Mercury in that it is quite dense for its small size.

PLANET III: Mephinos is Mars-like, with polar caps of water and carbon dioxide ice, and a cold and dry surface composed of rocky, cratered highlands and relatively smooth, nearly featureless lowlands. There are a number of very obvious dry river channels on the surface, along with corresponding erosional land forms, and many of these channels extend for hundreds of miles. Clearly, Mephinos was once quite wet. Today, as ide from some deep subsurface hot spots, it is largely geologically inert. It possesses two moons, one of which is a very small cratered ball, while the outer moon is a captured, irregular asteroid.

PLANET IV: NESSOS: This is a Panthalassic world, and the most masive planet orbiting either of the stars of the greater Alpha Centauri System. It has a substantial ring system, and a single large and cratered moon.

Thoughts are more than welcome. My biggest concern is the set up of Baahki and its moons, this world being the primary planet of interest for the system. I really like the idea of a planet being kept geologically active and habiutable due to lunar tidal influences, and hope that this is realistic enough to be able to keep.

Thanks!

...John...

How close is the first planet to the star? I'm just thinking that tidal forces would disrupt the orbits of moons that are orbiting it rather rapidly (I think they'd spiral in and hit the planet).

At the moment I have Baahki at a distance of 0.735 AU, which is the approximate centerline of the habitable zone. However, if this tidal stressing is a valid thought, then I don't need to worry about keeping the planet *that* close, and could conceivable move it out a bit further. A larger mass would help keep a thicker atmsophere, perhaps....

Dollan wrote:
PLANET IV: NESSOS: This is a Panthalassic world, and the most masive planet orbiting either of the stars of the greater Alpha Centauri System. It has a substantial ring system, and a single large and cratered moon.

Thoughts are more than welcome. My biggest concern is the set up of Baahki and its moons, this world being the primary planet of interest for the system. I really like the idea of a planet being kept geologically active and habiutable due to lunar tidal influences, and hope that this is realistic enough to be able to keep.

At the moment I have Baahki at a distance of 0.735 AU, which is the approximate centerline of the habitable zone. However, if this tidal stressing is a valid thought, then I don't need to worry about keeping the planet *that* close, and could conceivable move it out a bit further. A larger mass would help keep a thicker atmsophere, perhaps....

Thanks!

...John...

First, I like the idea of a more massive Baahki further from the parent star. Also, the "panthalassic" planet Nessos sounds cool. Just how large and massive is this planet? Later!

J P

Well, a Panthalassic planet is an actual theorized world. here are a couple of links:

http://arxiv.org/abs/astro-ph/0308324
http://arxiv.org/abs/astro-ph/0308159

I also have a somewhat older write up at the now out-of-date version of my Planetary Classification List (note that much of the PCL is written from a fictional point of view):

http://j.dollan.home.bresnan.net/ARCpclindex.html

Don Edwards is working on a remarkably beautiful system (I forget the name of it off hand, but it is a Henry Draper-named star), which features a Panthalassic world in the system. His visualization of it is absolutely wonderful.

...John...

A couple of screenshots of the project thus far:

HERE is the primary planet, Baahki. I need to tweak its size and mass and such, having accidentally used some smaller values than what I wanted originally. Also, it turns out that I made the texture more suited to a world tilted at a high degree of obliquity, so I did indeed turn the world on its side, as it were.

HERE is a shot of Baahki from the surface of its major and very clse moon, Strombolus (a cheeky name, I admit, and one that I will probably change in the near future). The moon has a rather dusty, if somewhat thin atmosphere, the result of it being highly volcanically active. Not that the night side of Baahki has some glowing areas. These are major volcanic zones, induced into activity by the gravitational interaction of the two worlds. I wasn't sure on the color of these zones, but I might change them to a more dulled red in the future. Also, Strombolus itself is, as of yet, untextured. I'm hoping to make something similar to Don's Orpheus texture, but I seriously doubt that I will come even close to his level of expertise and beauty!

Anyway, thoughts are always welcome!

...John...

VERY VERY nice..

Thanks, Beowulf!

I have to say, I'm pleased with how well the clouds came out. I used a real-time cloud map from THIS SITE, and for the first time used Photoshop rather than Paint Shop Pro. I'm a complete novice with Photoshop, but it certainly turned out much better than what I had hoped for. Paint Shop, I think, simply doesn't allow for the fine manipulation that Photoshop does.

Anyway, with any luck I can get started on the texture for Strombolus this week, and have it ready for a brief showing shortly after.

...John...

This add-on is looking very nice. I'm just slightly worried about the validity of putting a Panthalassic planet in the Alpha Centauri system - the formation process would seem to involve migrating a Uranus-like planet inwards, and the region far enough from the stars to form such a planet is probably not stable.

Hi Chaos...

I've been wondering about the same thing. In fact, I've been considering replacing Nessos with a fairly wide asteroid belt, but of relatively low population.

...John...

Thanks for the links on "Panthalassic" worlds. I found the info quite interesting. There might be a way to keep Nessos in the system. If it were me, I would first move Mephinos a bit inward. Then, I would move Nessos to where Mephinos is currently at. Finally, I would put Eutresca in orbit around Nessos.

One last note, the idea an asteroid belt sounds cool. Later!

J P