Celestia Forums

I found this article about the Tau Ceti system and how it has been found to contain huge numbers of asteroids, about 10 times as many as in the solar system.

I remember reading somewhere that Neptune migrated outwards during the formation of the Solar System leading to the clearing out of the Kuiper belt, could it be that Tau Ceti does not have a Neptune-like planet so its comet clouds were never cleared in this way?

I still don't get how they know it has 10 times as much material flying around the inner system...

And what would Sol's system look like from outside, I wonder? How big/bright would the disk we have be?

Some random thoughts on the Tau Ceti system....

This much material in the system, to my mind, may indicate a couple of things. One, perhaps the system is not as old as we have determined (about 5 or 6 billion, I believe, an estimate based on its low metallicity). If this is the case, and the star happened to form in a metal-poor environment, then perhaps we're looking at a young system still filled with planetoidal bodies, and planetary formation is currently underway.

Two, maybe the system IS this old, and for whatever reason large jovian worlds (or ANY Jovian worlds) failed to form here. in that case, there may be a family of terrestrial worlds here, but there is still a huge amount of left over planet-forming material.

One interesting system schematic, mentioned by Steve Bowers, is that perhaps this system resembles Saturn's rings in a way. A number of orderly belts filled with divisions, where terrestrial worlds do orbit. I don't know if it would really look any different to the naked eye than any other system (even with the greater amount of material, asteroids and comets are still SMALL and probably relatively dark).

For my own setting, I've gone with Steve's thoughts, although I've fudged things enough so that there IS a Gaian world present. The kicker, of course, is that technically the metallicity is so low in this system (0.37 of Sol, which is below the standard 0.4 cut-off for the formation of terrestrial worlds) that large terrestrials probably aren't present anyway.

Of course, I could easily be wrong!

...John...

Yes, well to argue with my own idea, Saturn's rings aren't stable over the long term; they will gradually fall into the planet...

but this is probably because of interaction with the magnetic field and atmosphere of Saturn, isn't it?

If Tau Ceti has one or perhaps a couple of smallish gas giants, the asteroid belt could be shepherded into stable bands.

Just a guess, unsupported by any maths.

But I did find a PDF once somewhere on the net which divided the asteroid belt up into several bands, each named after a particular asteroid, in harmonic relationship with Jupiter.

Like the complete amateur I am I can see the comparatively dense Tau Ceti asteroid belt in my mind's eye, with large gaps or divisions each occupied by a shepherding planet...

Feasible?

Steve

I don't see why it wouldn't be feasible. As far as I know, there is a completely different set of dynamics running the asteroid belt and the Saturnian ring system. But there ARE the so-called Kirkwood Gaps in the asteroid belt, caused by gravitational resonances with Jupiter. I could see such gaps forming in a system with some gas giants, or even very large terrestrials.

One thing I'm waiting for is some data on the distance ranges of the Tau Ceti asteroids. Does the observed field stretch to within a certain number of AU's from the primary? Is it detectable as far in as they can observe?

...John...

Even if Tau Ceti does have "tens times as many asteroids and comets", I'm still not seeing why this makes the system uninhabitable. Who's to say that they aren't all herded into stable belts, and there are no more rogue bodies than there are in our own solar system?

This is wat I am thinking, and what I am assuming for my setting's Tau Ceti system. I have a hunch headlines like that tend to make the story a little more worthwhile, as far as reporters go. It sounds like the scientists are thiking of a planet where a KT-type impact occurs every 6 million years or so. Of course, we really STILL don't know what all the effects of that impact were, and if it did little more than cap off an already present string of problems for that era.

If Tau Ceti IS as old as it is supposed to be, then I would easily believe that everything in the system is, more or less, orderly.

Myself, I'm fascinated by ANY new news on our local neighborhood stars!

...John...

Evil Dr Ganymede wrote:Even if Tau Ceti does have "tens times as many asteroids and comets", I'm still not seeing why this makes the system uninhabitable. Who's to say that they aren't all herded into stable belts, and there are no more rogue bodies than there are in our own solar system?