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GOURDHEAD
2004-Dec-02, 03:49 PM
Here (http://www.space.com/scienceastronomy/sun_planets_041201.html) article speculating about effects on the early solar system.

antoniseb
2004-Dec-02, 04:26 PM
I was about to post a link to the CNN copy of the same story. This is an interesting story, since the orbit of Sedna et al. lends additional credibility to the idea that the Sun was formed in a dense stellar nursary.

Fraser
2004-Dec-02, 06:40 PM
SUMMARY: Astronomers from the Harvard-Smithsonian Center for Astrophysics believe it's possible that our own Sun could have stolen some material from other stars billions of years ago. They came to this conclusion while trying to understand the orbit of Sedna, which takes 10,000 years to go around the Sun, in a highly elliptical orbit far beyond the Kuiper Belt. When our Sun was younger than 200 million years old, it could have swept past another star, disrupting the Kuiper Belt, and trading large objects (like Sedna) with each other.

View Full Article (http://www.universetoday.com/am/publish/sun_material_collector.html?2122004)

What do you think about this story? Post your comments below.

Duane
2004-Dec-02, 07:08 PM
This is really quite an amazing story, although frankly is shouldn't be that much of a surprise. Work done by Arizona State University's Jeff Hester recently identified Fe60 in meteorites that suggested the Sun's enviroment was irradiated by a nearby supernova after it's formation. The article would seem to add to the evidence that the Sun formed in a knot of material along with many other stars.

Other researchers have noted that many meteorites display evidence of multiple injection events from before, during and after the formation of the sun.

This quote from the article:


Kenyon and Bromley's simulations indicate that thousands or possibly millions of alien Kuiper Belt Objects were stripped from the passing star.

along with their suggestion that the encounter happened when the sun was only 20 to 200 million years old makes me wonder if this could correspond to the period of heavy bombardment. If it does, who knows, maybe water and other material stripped from the passing star and impacting on the very early Earth helped to seed this planet.

Pretty interesting stuff.

Greg
2004-Dec-02, 07:36 PM
Wow, this article provides a wealth of topics to explore. One thought to include is that this is not the only possible explanation of Sedna's unusual orbit. Explaining the gap of objects in the Kuiper belt is harder to explain. I think this article is the best explanation I have heard yet as to how that may have happened. I like the idea that such an interaction could have contributed to the period of early bombardment as such a disruption in the outer solar system would surely have sent lots of small to medium sized objects swirling into the center of the solar system.
The good news is that the theory should be easy enough to prove as it implies that there should be a whole bunch of objects coorbiting in a highly inclined orbit at a certain distance from our sun (the captured objects.) Since nobody has had reason to look for objects at this inclination before, a search may indeed turn them up.
If the interloping star formed in the same stellar nursery as our sun, then it is likely that its objects would not be so different than objects in this solar system. I would have thought that some unusual isotope ratios would have been found in some meteorites by now to lend support to this theory. Perhaps an absence of such meteorites argues against it. Perhaps looking at isotope ratios in past comet ejecta might provide more useful information on this topic. Could studying material in comet tails as they go around the sun show a difference? I suppose the orbits of such comets would also be highly inclined and I do not recall hearing of any comets with this kind of orbit. It may be that finding evidence from comets or meteorites may be harder than finding a meterorite from Venus (to my knowledge none have ever been identified from Venus.)

StarLab
2004-Dec-02, 07:37 PM
Alright, sorry guys, but I'm letting out my steam...

Why do you guys think this is NEW?! :o This is not new! People have been saying for years that our Solar System could have intercepted another star system! This is nothing new! :ph34r:

antoniseb
2004-Dec-02, 08:04 PM
Originally posted by StarLab@Dec 2 2004, 07:37 PM
Why do you guys think this is NEW?!
Actually, you are right that its been said before, especially during the few weeks after the announcement of the discovery of Sedna. What is new here is that a more detailed set of simulations were run, showing what that the cheaper simulations pretty much got it right. Some additional specifics were added.

lswinford
2004-Dec-02, 08:26 PM
I think it adds some additional credence to those older ideas. That's a lot of computer time for JPL to give up and the JPL people are not sloppy, so it adds tremendous credibility.

I find it hard to imagine that we have 4 billion years of stability to the orbits of the major objects in our solar system, however. But I do recall conjecture some 30-40 years ago about Pluto's eccentricity possibly indicating a capture from elsewhere at some time in the very distant past. I think when some of the older people were petitioning to have a Pluto probe retained after being scrubbed from a certain president's reprioritizing of NASA's projects list, the older folks may have had that in mind--seeing if it is like the rest of our solar system or if something is so strikingly different as to indicate another system as its source.

wstevenbrown
2004-Dec-02, 10:41 PM
All right-- somebody's gotta say it: How do we link all of this with the axial tilt of Uranus? Out where the weather's chilly, most of the reasons for chaotic axial wobbles just don't apply. S

Duane
2004-Dec-02, 10:56 PM
Steve, so I don't have to repeat myself, please take a read of the last couple of posts here: http://www.universetoday.com/forum/index.p...topic=5495&st=0 (http://www.universetoday.com/forum/index.php?showtopic=5495&st=0)

wstevenbrown
2004-Dec-02, 11:38 PM
OK. Hadn't looked there recently. Has anyone put pencil to the excess heat generated by such an event, with an eye toward setting an upper limit on its date? Uranus seems to be about as cool as it should be if it formed where it is and experienced no catastrophes. This naively suggests that it formed farther out and moved inward as a result of the bump. But Neptune was unaffected-- even if it was on the far side of the sun at the time, the interloper would have had to be a high-mass, fast moving object, rather than a solar nursery-mate. Hmm... the Velikovsky business is high-risk. Oops-- gotta go, S

Duane
2004-Dec-02, 11:46 PM
I wonder how big an object would be needed, depending on trajectories. Actually, a better way to put it would be how small an object could be. I would think part of the answer would depend on the speed of the impactor.

I would like to see some calculations on this. Now, where DID I put that sliderule....

Duane
2004-Dec-02, 11:56 PM
Some random thoughts about this.

Dr Manuel's outgassing episode at 200 million years is the same number suggested for the period when this close pass with another star stripped thousands or perhaps millions of comets from the Kuiper belt. It is also the same age suggested for the collision between the proto-earth and the mars-sized impactor that formed the moon.

Here's a scary thought. What of they are all connected? Here's the scenerio.

The Earth and a companion in one of it lagrange points formed by accretion over a period of ~200M years. At about that time, the solar system brushed past another star, disturbing the orbits of millions of Kuiper belt objects. Hundreds of thousands of these objects come pouring into the central region of the solar sytem, striking everything forming at the time.

Some of these objects are large, large enough to have formed spheres due to their own gravity. One of these large objects strikes the mars sized object, jarring it out of the Lagrange point and putting it on a collision course with the proto-earth.

This might explain other mysteries, such as Venus's pro-grade rotation and Uranus' tilted equator.

Further, over the course of the next couple of million years, the objects that missed everything and went back out in their orbits continually return until they are flung out completely, impact something, or fall into the sun. That would help to explain how the moon shows evidence of the heavy bombardment period.

So, what do you all think?

om@umr.edu
2004-Dec-03, 12:36 AM
Interesting.

This report suggests that some objects in our solar system may have "actually formed around another star."

Do they think this can explain the "Strange" Xenon observed in Jupiter?

http://www.umr.edu/~om/abstracts2001/windl...leranalysis.pdf (http://www.umr.edu/~om/abstracts2001/windleranalysis.pdf)

With kind regards,

Oliver
http://www.umr.edu/~om

antoniseb
2004-Dec-03, 03:48 AM
Originally posted by om@umr.edu@Dec 3 2004, 12:36 AM
Do they think this can explain the "Strange" Xenon observed in Jupiter?
I bet, that if you read the paper carefully, "Strange Xenon" isn't even mentioned.

om@umr.edu
2004-Dec-03, 04:59 AM
I suspect you're right, Anton.

But when they choose to address such observations, material captured from a nearby star offers another convenient explanation for "Strange" Xenon and other nucleosynthesis excesses of isotopes made by specific nuclear reactions like He-burning, the s-process, the p-process and the r-process.

With kind regards,

Oliver

http://www.umr.edu/~om

StarLab
2004-Dec-03, 05:01 AM
Wow, Oliver, you must be having a lot of fun with this string... ;) :lol:

Duane
2004-Dec-03, 05:13 AM
But when they choose to address such observations, material captured from a nearby star offers another convenient explanation for "Strange" Xenon and other nucleosynthesis excesses of isotopes

That's a very good point, assuming that by convenient you also mean possible. Would a large number of impacts of Kuiper belt objects create the Xe isotopes you observed in Jupiter?

guest_star
2004-Dec-03, 06:30 AM
Altough I like the idea of planets being formed by material ejection from the Sun, which IMO explains Venu's rotation, Duan's scenario is quite appeiling.

I imagine massiv object rushing between Proto-Earth and Proto-Venus and very close to the third planet between those two, altering Venu's rotation (and revolution path to some degree) and The Third Planet's rotation and path placing it in Protho-Earths orbit.
Proto-Earth clashes The Third Planet and bang! giving birth to Earth & Moon.

Is this possible with regard to Venu's, Earth's and Moon's angular momentum?

om@umr.edu
2004-Dec-03, 03:33 PM
Originally posted by Duane@Dec 3 2004, 05:13 AM
Would a large number of impacts of Kuiper belt objects create the Xe isotopes you observed in Jupiter?
Not likely, Duane.

Impacts of Kuiper belt objects could not create the "Strange" Xenon isotopes that the Galileo probe measured in Jupiter - - - unless those impacts also produced the solar system's primordial Helium.

Primordial Helium at the birth of the solar system was trapped in meteorite minerals with "Strange" Xenon (Xe-2), but not in the meteorite minerals that trapped "Normal" Xenon (Xe-1).

For example, analyses on minerals in the Allende meteorite show primordial Helium with "Strange" Xenon (Xe-2) and no He in the minerals that trapped "Normal" Xenon (Xe-1).

http://web.umr.edu/~om/images/Xe-2_He_in_m..._meteorites.gif (http://web.umr.edu/~om/images/Xe-2_He_in_meteorites.gif)

http://web.umr.edu/~om/images/Xe-2_He_in_m..._meteorites.jpg (http://web.umr.edu/~om/images/Xe-2_He_in_meteorites.jpg)

See "Heterogeneity of isotopic and elemental compositions in meteorites: Evidence of local synthesis of the elements ", Geokhimiya No. 12 (1981) 1776-1801 [In Russian].

With kind regards,

Oliver
http://www.umr.edu/~om

Duane
2004-Dec-03, 06:01 PM
Oh well, kind of figured as much.

It would have been an amazing (and terrifying! :ph34r: ) sight to see hundreds or thousands or more comets in the night sky for weeks on end as these Kuiper belt objects came pouring into the central part of our solar system. I really do wonder if this could have been the era of heavy bombardment.

Guest
2004-Dec-03, 10:28 PM
It is just as likely that there was enough chaos in the early solar system to explain these events without including this scenario. As far as the Earth-Moon impact event, it is entirely consistent within this theory that such a collision would happen within the timeframe that it did anyway. If a Mars-sized planetoid formed at the LaGrange point (L3) it would have to collide with Earth within 500 million years since it's orbit would not be stable. The Lagrange point theory might be a better way of trying to understand what happened to Uranus and Venus. The question about Pluto is a good one and while we are at it I would throw in Triton as well. This was likely a large KBO that got captured by Neptune in a decaying retrograde orbit. I would love to be around to see what happens when that collision happens. (of course by then humaninty may have become extinct long before.)

Guest
2004-Dec-04, 02:17 PM
Was the Earth stolen from another star? Maybe the earth or some organic structures are older than the sun. While this is a Velikovsky-like speculation this evidence of the exchange of material should open this speculation. A lot of our cosmological standards are predicated on the assumption that the sun is older that its satelites and perhaps a lot of astro physical paradoxes could be resolved by exploring the alternative possibility. What a lot of the nimrods in science (too many with degrees) are unable to grasp is that "good" logic and the scientific method of analysis do not require that simplest mundane solution is automatically the right one. It is usually the first to be explored and only sometimes proven to be correct through experiments. Until there is solid proof it is valid and fruitful to explore other explanations. For instance until we know what formed the shapes on Mars it is in fact just as "bad" logic to declare it could only have been carved by the wind anymore than it is correct to say Mount Rushmore must have been carved by the wind because it is the simplest explanation. Infact only a "bad" logician would attach "good" or "bad" to the word logic.

Guest_Gerald Lukaniuk
2004-Dec-04, 02:29 PM
Earth older than Sun. To further my point about the earth or mars or organic-like structures on either might be older than the sun while this solution might be fruitful in explaining primordial ice ages and mass extinctions and resetting the cosmic clock it still has a medium to low probability of having occurred in light of this recent observation.

om@umr.edu
2004-Dec-04, 03:37 PM
Originally posted by Guest@Dec 4 2004, 02:17 PM
Was the Earth stolen from another star?
An interesting idea, Guest.

Measurements in the 1960s revealed that the abundance pattern of Xenon's nine isotopes in average carbonaceous chondrites is unlike that on Earth or in the Sun.

To distinguish these three types of Xe, papers then referred to AVCC Xe (Average Carbonaceous Chondrite), AIR Xe (Earth) and SOLAR Xe (Sun).

These three types of Xenon are shown by the large points labeled V (AVCC), A (AIR) and S (SOLAR) in Fig. 1 of the 1972 paper, ""Xenon in Carbonaceous Chondrites", Nature vol. 240 (1972) pages 99-101.

http://web.umr.edu/~om/archive/XenonInCarb...sChondrites.pdf (http://web.umr.edu/~om/archive/XenonInCarbonaceousChondrites.pdf)

Measurements in the 1970s revealed "strange" isotope abundances of many elements in meteorites. Interpretations of these observations progressed as follows:

1. Super-heavy elements generated fission products in meteorites.

2. No, the "strange" isotope abundances are from nucleosynthesis.

3. Meteorites contain interstellar grains with "strange" isotopes.

4. No, un-mixed supernova debris formed entire meteorites.

5. SN debris formed planets and the Sun, but the SN debris is masked by severe mass separation that enriches light elements (H and He) and light isotopes of each element at the solar surface.

When #3 was in vogue, Earth's Xe seemed distinct from Xe in meteorites and Xe in the Sun. We used to joke that Earth must be a giant, interstellar grain !

We have since learned the Sun has AIR Xe, like Earth, but light isotopes are enriched at the solar surface and in the solar wind by 3.5% per mass unit !

Thus, it now seems certain that Earth is not a giant interstellar grain stolen from another star.

With kind regards,

Oliver
http://www.umr.edu/~om

lswinford
2004-Dec-09, 04:21 PM
BTW, we have to at least add another zero to Duane's number. Some 200 million years is entirely too recent for most time scales, a couple of billion years then I'm tracking with you for most of the discussion. ;)

Duane
2004-Dec-09, 04:53 PM
Actually iswinford, the 200 million number comes from this article, Dr Manuel's noble gas studies, the period of heavy bombardment, and the proposed formation date of the moon. It seems to me it is quite a coincidence that they are all in the same date range, and I don't like coincidences in science.

Guest_Gerald Lukaniuk
2005-Jan-02, 11:09 PM
Dr Manuel's incite into the nature of the true nature sun is ingeious and
I appreciate him taking time to review my speculations and share pertainent info. On the topic of xenon I once passed up the opportunity to purchase some rutilated quartz in Northern Ontario that contained some of the controversial xenon bubbles attributed to titanium decay that indicated the deep strata igneous rock was extremely younger than the estimated age of the earth. I haven't reviewed current speculation or how or if the dilemma was resolved but I suspect it should involve a major revision of some well entreched time constaint. I/ve toyed with the speculation that rates ofradioactive decay might have at least one external remote influence. Certainly a great body of work exist to imply an internal clock work and fission chain reactions involve slow neutron/nuclei collisions but what if there was another agent the was relatively omni present but could fluxuate or be shielded or generated perhaps by slow neutron interactions. Not able to imagine a way to measure such an influence or even where to look I've entertained myself with a thought experiment to consider wether a pure sample of a artificial produced sample of a radio isotope with a specific birthday would desplay the same half life as a sample that is an aggragate of the same isotope but having components with different "birthdays". I appolgize if this is already a mundane and disproven speculation but I'm concerned that the current state of cosmology is fast becoming what the precise scince of chemistry was like when it was called the "A" word
Gerald Lukaniuk