Asteroid belts are rare???

[Peter Newman]

http://www.space.com/18326-asteroid-belt-evolution-alien-life.html

Asteroid belts similar to the one between Mars and Jupiter appear to be rare beyond our solar system, implying that complex alien life may be rare as well, a new study reports.

Fewer than 4 percent of known alien solar systems are likely to have an asteroid belt like the one in our own neck of the woods, researchers found. Belts that look like ours may help spur the evolution of life, seeding rocky planets with water and complex chemicals but not pummeling the worlds with a constant barrage of violent impacts.

"Our study shows that only a tiny fraction of planetary systems observed to date seem to have giant planets in the right location to produce an asteroid belt of the appropriate size, offering the potential for life on a nearby rocky planet," study lead author Rebecca Martin, of the University of Colorado in Boulder, said in a statement. "Our study suggests that our solar system may be rather special."

OBTrav - Note that they're not saying that only 4% of systems have one or more planetoid belts, just that only 4% have one similar to our solar systems.

 

[BytePro]

Good post, but pathetic thread title Peter! :nonono:

 

[HG_B]

These guys are talking out of their hat. They have ZERO clue as to whether or not a belt helps or harms development of life in a solar system. They have to write something to draw paychecks. But, good enough for a game of total fiction. Maybe incorp into system dev rules.

 

[aramis]

These guys are talking out of their hat. They have ZERO clue as to whether or not a belt helps or harms development of life in a solar system. They have to write something to draw paychecks. But, good enough for a game of total fiction. Maybe incorp into system dev rules.

Yup. Agreed.

Totally bogus even on its face.

We can just barely detect worlds the size of Mars in venusian orbits - asteroid belts are likely darker material (low albedo), not pinpoint gravity sources (thus no stellar wobble), and tiny (thus low illumination).

We should, for example, be able to pick up the mars-sized world in the AC system - as a single pixel point of light - by optical means... but it's doubtful such optical search could find asteroids orbiting AC, and far less likely that they could do so in the ecosphere or beyond.

 

[Enoki]

These guys are talking out of their hat. They have ZERO clue as to whether or not a belt helps or harms development of life in a solar system. They have to write something to draw paychecks. But, good enough for a game of total fiction. Maybe incorp into system dev rules.

Agreed. I'd say that their ability to even determine the presence of a belt in a another solar system at this point is very suspect. As to how life starts they definitely have little clue there, if any at all. On the whole this is pure speculation on the writer's part.

 

[rancke]

Don't forget that whatever the frequency of asteroid belts are in our reality, the part of Charted Space where the Ancients used to bob and stomp has a considerable number of extra ones.


Hans

 

[BytePro]

Peter's sensationalist and blatantly misleading thread title puts a negative spin on things... my own gut reaction was pretty much in line with prior posts...

To be fair - the actual authors are mostly quoted out of context and for max 'journalistic' drama.

Space.com is, after all, just a social media site spitting up distorted, re-hashed information just as largely misleading, inaccurate and full of crap as most any main stream media today. (This one even mis-attributes a direct quote I think...)

For the real 'story', here is the actual paper - http://arxiv.org/pdf/1207.4284 - which you will note is not referenced in the blurb - i.e., 'Here's your sign!' as Foxworthy might say!

Note that most peer reviewed and published papers are available for free (legitimately!) from original authors' sites, related institutions or from peer review sources.

[src: http://cpr-astrophep.blogspot.com/2012/07/12074284-rebecca-g-martin-et-al.html ]

 

[HG_B]

We can just barely detect worlds the size of Mars in venusian orbits - asteroid belts are likely darker material (low albedo), not pinpoint gravity sources (thus no stellar wobble), and tiny (thus low illumination).

We should, for example, be able to pick up the mars-sized world in the AC system - as a single pixel point of light - by optical means... but it's doubtful such optical search could find asteroids orbiting AC, and far less likely that they could do so in the ecosphere or beyond.

That's what I thought. The likelihood of spotting an asteroid belt is VERY low.

 

[aramis]

That's what I thought. The likelihood of spotting an asteroid belt is VERY low.

FYI, the separation is plenty, and the Keck interferometer should be able to resolve the world as a single pixel. It's bright enough that it SHOULD be visible if the albedo is no lower than the moon's, and big enough to be half a pixel in size.

But only if it's in quarter... at full, unless tilted heavily, it's too close to the star (lost in the glare), and at new, too dark.

 

[robject]

I didn't bother reading the article, so forgive me if I veer from the topic. Also forgive my ignorance about Jupiter:

However, isn't it the case that the belt essentially "stopped" Jupiter in its march inward, i.e. by sweeping away most of the debris that had allowed Jupiter to work its way inward, into its present orbit? Wouldn't Jupiter have proceeded to eat (or dislodge) the insystem otherwise?

 

[coldwar]

After reading the first post I laughed. Sorry but I did.
Firstly as others have mentioned, we have no way of seeing an asteroid field in any potential effect in another system. Next would be, which I believe hasn't been mentioned. How many systems are we able to currently view to detect any sort of planet in orbit around it's star? Then put this answer against the amount of stars we already know of in just our own galaxy. I'm sure those systems we can potentially see orbiting objects is a tiny percentage of the entire systems with in our own galaxy.

Next thing I'm going to say about, we know stars upon creation create fields of debris. If there is no debris, there is nothing to orbit the star at all, except rogue's that are brought in to an orbit, which are rare in the first place. Noticed something someone said. It is currently believed that some of the planets in our system were much further inwards then they are today. Thanks to Jupiter and Saturn meeting at regular intervals on their orbits they pulled/ pushed other planets in to different orbits. One was believed to be changed dramatically. Neptune, which was on a inside orbit and got thrown out to its current orbit by Jupiter ad Saturn.
Also, studies of Saturns rings have helped use understand how a system comes together. And is used to support the above paragraph too. This alone would also disprove that you need a large outer orbit object to have a belt.

(My statements come from watching the BCC's documentary's by Prof. Brain Cox, "Wonders of the Solar System")

 

[Carlobrand]

After reading the first post I laughed. Sorry but I did.
Firstly as others have mentioned, we have no way of seeing an asteroid field in any potential effect in another system. Next would be, which I believe hasn't been mentioned. How many systems are we able to currently view to detect any sort of planet in orbit around it's star? Then put this answer against the amount of stars we already know of in just our own galaxy. I'm sure those systems we can potentially see orbiting objects is a tiny percentage of the entire systems with in our own galaxy.

Next thing I'm going to say about, we know stars upon creation create fields of debris. If there is no debris, there is nothing to orbit the star at all, except rogue's that are brought in to an orbit, which are rare in the first place. Noticed something someone said. It is currently believed that some of the planets in our system were much further inwards then they are today. Thanks to Jupiter and Saturn meeting at regular intervals on their orbits they pulled/ pushed other planets in to different orbits. One was believed to be changed dramatically. Neptune, which was on a inside orbit and got thrown out to its current orbit by Jupiter ad Saturn. ...

I think laughing about it's a bit unfair. Everyone's excited about the new ability to infer data about nearby stars, and there's a lot of speculation evolving from the early findings. That's to be expected. Our understanding of our own solar system's evolution was mostly speculative as well until recently, and it's still a subject of disagreement and riddled with unanswered questions. I think - I certainly hope - that we all know there's still a lot of uncertainty and nobody's taking what's coming out of the extrasolar studies as gospel (at least in this forum - I am a good deal less confident about the public in general). At the same time I think tossing around - and criticizing - these ideas is an important part of science.

I'm not entirely clear what you're saying about Neptune, specifically what you mean by "inside orbit". I was given to understand that the Jupiter-Saturn-Uranus-Neptune set were collectively closer and migrated outward as a result of interactions with the aforementioned debris and each other (which may explain some of what we're seeing in other extrasolar observations). However, I thought the Nice model had the four of them starting "life" more or less in their current arrangement, just closer in - although I understand there's some chance Neptune and Uranus may have traded places.

 

[HG_B]

However, isn't it the case that the belt essentially "stopped" Jupiter in its march inward, i.e. by sweeping away most of the debris that had allowed Jupiter to work its way inward, into its present orbit? Wouldn't Jupiter have proceeded to eat (or dislodge) the insystem otherwise?

No. Jupiter has a stable orbit with or, without the almost massless asteroid belt.

 

[coldwar]

I'm sorry, I may have been over zealous in saying what I said about laughing, I agree. That was my personal reaction. But please no one take it to heart. My mistake.

The documentary didn't say what its closer orbit was. So, my own interpretation is the same as yours. I was just mentioning the basis of the phrase that Brain Cox used, which in itself is very unambiguous. However, in response to you. The documentary also showed a model of the inner orbits (Mercury, Venus, Earth and Mars) plus Saturn and Jupiter, didn't go further out. However there were other objects in orbits in the inner orbits. The model showed the solar system before it went through, what is believed to have been the most turbulent time in the solar system. (Forgotten the name of the period of time, but I know of its result) which then resulted in many of the planets and moons to be bombarded heavily by Comets and asteroids.
Slightly after this period, all the planets ended up finding new orbits. Mainly caused by the pulls and push's of gravity caused by Jupiter and Saturn. Forgotten the name of this gravitational effect. The effect is also seen in Saturn's rings, whereby parts of the ring are pulled further outwards, notable making the Cassini Division. On the larger scale, it is believed to have caused the turbulent period of time I spoke about in my above paragraph.

 

[Whipsnade]

I'm not entirely clear what you're saying about Neptune, specifically what you mean by "inside orbit".

I believe he's referring to the current belief that Uranus and Neptune "swapped" orbits after forming.

I've seen the program he's referring to. The main point being made in it is that planetary orbits are not stable over deep geological time spans. We tend to forget that even if we once knew it.

Jupiter, the 800 lb gorilla of the Solar System, is responsible for much of "structure" we're with which familiar. It's gravity forced the smaller planets inward and the larger ones outward as they formed. In conjunction with Saturn, Jupiter forms a gravity pump of sorts as both giants' orbits are in resonance with each other. One example given of this pump's effect is that Mercury's orbit is going to be eventually elongated enough to cross Earth's orbit.

Thanks to the flood of data concerning extrasolar planetary systems one thing is very certain: ALL Traveller sysgen methods are seriously broken at a fundamental level. We grouse about starports not matching populations or populations not matching planetary conditions when it more and more apparent we can't even produce the "right" kind of planets in the "right" kind of orbits.

 

[coldwar]

Thanks to the flood of data concerning extrasolar planetary systems one thing is very certain: ALL Traveller sysgen methods are seriously broken at a fundemental level. We grouse about starports not matching populations or populations not matching planetary conditions when it more and more apparent we can't even produce the "right" kind of planets in the "right" kind of orbits.

For World creation for me, I'm not picky about moving a world to some where it makes sense. For example, I roll the main world, and it's size and atmosphere are like Venus's and its in the habitable zone. The sun is similar to ours, Or the sun is different slightly. I then kick it an orbit closer and get rid of any population I made for it. (Generally I just make population etc after finding likely worlds that can support life, then move to worlds where one can make habitats if they can get the required technology there. Some planets I even change the resulkting numbers of atmosphere or hydrographic's to something that makes sense.) Then planets that make no sense to terraform or even have habitat domes etc, I don't touch.

The rest of your post Whipsnade, thank you. Done a little checking. Orbital Resonance is the name of the activity that I and you are talking about. The interesting thing, if I remember correctly, the same process slowed the orbits of the inner planets to, obviously by making more somewhat stable orbits for them.

 

[Peter Newman]

After reading the first post I laughed. Sorry but I did.

I meant for the thread title to end in a question mark. I didn't really buy it either.

To me the most interesting part of the article was the notion that having a gas giant move to an inner orbit, which extra solar planetary data suggests is quite common, will probably really mess up any asteroid belts (and planets) in intermediate orbits. In Traveller terms the belt will probably still be there but it is going to be thinner.

 

[aramis]

I meant for the thread title to end in a question mark. I didn't really buy it either.

Fixed.

To me the most interesting part of the article was the notion that having a gas giant move to an inner orbit, which extra solar planetary data suggests is quite common, will probably really mess up any asteroid belts (and planets) in intermediate orbits. In Traveller terms the belt will probably still be there but it is going to be thinner.

I doubt the belt would remain as a belt. Most of it should be gathered by the GG - they're big enough to clear their orbits, mind you... What isn't cleared winds up in trojan points.

(Keeping in mind that, if they don't sweep their orbits clean, they aren't planets according to the IAU. )

 

[Fritz_Brown]

What isn't cleared winds up in trojan points.

Since trojan points aren't something that has a UWP code, how would you identify them? As a belt?

 

[aramis]

Since trojan points aren't something that has a UWP code, how would you identify them? As a belt?

Certainly not. technically, they're moons with orbital distances measured in AU...