Ultimate Solar System contains 60 Earths in a Binary System

[omega_tyrant]

http://www.newscientist.com/article/dn25...40cGlyFXHg

I know there are even more spectacular configurations in OA, but I still found this intriguing. It would be interesting to set up a system like this in the setting. Since this was done with red dwarf stars, I wonder if the amount of planets could be increased if G stars were used?

Also, it would be good to hear if anyone objects to this from a purely physical/gravitational standpoint.

[Drashner1]

I don't have the background to raise objections from a physics background (or guess if a G-type star would allow a substantially larger habitable zone) , but the idea itself is fun. I would expect that in OA, this sort of thing would be a construct - whether by Terragens or some long vanished xenosophont race.

Todd

[radtech497]

I don't have the background to raise objections from a physics background (or guess if a G-type star would allow a substantially larger habitable zone) , but the idea itself is fun. I would expect that in OA, this sort of thing would be a construct - whether by Terragens or some long vanished xenosophont race.

Todd

Using a G-type yellow dwarf instead of an M-type red dwarf would more than quintuple the size of the liquid water zone (0.103 AU wide for a generic M0V versus 0.543 AU wide for a generic G0V). So it would be possible to add more intra-HZ orbits around a G-type dwarf.

On the other hand, using the binary red dwarf pair as described might lead to some issues. Planets orbiting within the HZ of such stars tend to be locked into a spin-orbit resonance with their primary (though not necessarily a 1:1 resonance, which is probably not the case in such a crowded system). Tidally-locked worlds are unlikely to possess moons, because of their relatively small angular momenta.

Second, the presence of so many worlds in such a small region will soon produce a plethora of orbital perturbations, which introduces and then magnifies orbital eccentricities, increasing the risk of planetary collisions and/or ejections. In short, such systems as described are unlikely to survive very long. (An artificially-constructed system of this type is likely to require constant monitoring and maintenance).

The jovians with Earth-sized moons are likely to be much more massive than Jupiter. In that case, the gravitational reach of each of these worlds would serve to reduce the number of jovians that can coexist in the HZ.

As for practicality, these systems can be considered highly impractical since about the same habitable area can be provided for much less effort and expense with a single McKendree cylinder. Still, the Sephirotics (or at least some of them) are known for wildly impractical megaprojects, so it isn't out of the question for something like this to exist somewhere (though convincing potential residents to live in such systems might be a problem).

Radtech497

[stevebowers]

Something like this might be a long term project in a Bok Globule, where the formation of planets is controlled (probably using mass-stream technology) to favour the formation of habitable pairs of planets. The system might be ready to inhabit in a million years, or less if active cooling technology is used.

[stevebowers]

The main drawback with the scheme is the habitability of twin planets. If they are tidally locked the days will be long - if they are not there will be big tides, earthquakes and volcanoes.

[radtech497]

Actually, I'm somewhat leery of binary planets existing where one or both is tidally-locked to its primary (in the case of the red dwarf configuration described in the article) because of the low values of planetary angular momentum. IMO, the planets would, as their rotation slowed, move farther from their co-orbiting partner until they escaped beyond their partner's Hill sphere radius.

Radtech497

[stevebowers]

No binary planet can exist for long if one planet is tidally locked to its primary; as you say, the other planet will migrate away and become a separately orbiting planet. Note that these two newly separated planets will still be unusually close to each other - they will continue to interact periodically until they fall into a new wider separation (or possibly hit each other, as in Pelion and Ossa in OA).

However many, if not most binary planets will be tidally locked to each other, or at least the smaller one will be locked to the larger one, as in the case of the Earth and the Moon, which is sometimes considered a binary planet. The other example of binary objects in our Solar System, Pluto and Charon, are both mutually locked.

This image, from Sean Raymond's original article, shows how two mutually locked planets would look; this arrangement would be stable for billions of years, and produce only small tides (although these two worlds are closer than most such worlds would be- they are almost contact binaries, like Harmonic Resonance in OA)

[Rynn]

Huh, so two tidally locked planets could build an elevator from one to the other right?

[stevebowers]

Yes, although some of them (like Neli-Neti, which I described recently) would probably be too far apart for that.

[Rynn]

Yes, although some of them (like Neli-Neti, which I described recently) would probably be too far apart for that.

Hmm. I imagine that the length issue could be overcome by using magmatter strengthened material like in a banks orbital.