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To me, the interesting thing is that this iceteroid (love the term!) is definitively extra-solar and that means that it is likely that other systems have both a

To me, the interesting thing is that this iceteroid (love the term!) is definitively extra-solar and that means that it is likely that other systems have both asteroids and comets. Though we've seen asteroids in other systems like Fomalhaut [0], we've not been up close and personal with the compositions of extra-solar material. Here in the Sol system, we have a pretty strange arrangement of planets [1], with big ones all in the outer system and smaller ones in the inner system. So looking at just our system is not very indicative of 'typical' system evolution, in terms of iceteroids. Once we figure out where Oumuamua came from, that'll give us some idea of the compositions and evolutions of other systems (data point of 1 is better than 0), like the frost line. Oumuamua should be viewed as awesome and exciting, but as the tip of the ... iceberg ... when it comes to the real questions of stellar evolution and all the awesome stuff happening there. [0]https://en.wikipedia.org/wiki/Fomalhaut https://en.wikipedia.org/wiki/Fomalhaut [1]https://en.wikipedia.org/wiki/Nice_model https://en.wikipedia.org/wiki/Nice_model

InclinedPlane 8y ago
Good point. One thing we learned from exoplanet hunting is that there is a much greater diversity out there than we had originally thought, implying that planet formation is a lot more of a dynamic process than our previous models indicated. Prior to the discovery of exoplanets our planet forming models were very much "over fit" to the example of our own Solar System, giving the impression that other stellar systems would end up looking similar to our own. The reality is that our Solar System is, as you say, probably unusual. One aspect of this is that it seems like planetary migrations are pretty common (both inward and outward). If that sort of thing happens early during planet formation then it could easily explain an "asteroid" (which we understand is almost certainly a planetessimal fragment, though many asteroids are just that) which has acquired additional material including ices. The obvious followup here is that we need way, way more closeup observations of small bodies in our own Solar System, we probably also need to develop better techniques for observing interstellar interlopers, and we need to improve our studies of extrasolar planetary systems. Fortunately the first part is already covered, between the Hayabusa 2, Osiris-REX, Lucy, Psyche, and New Horizons missions we should collect a lot more information on such bodies. However, it's probably going to be a long time before we have answers even to simple questions like the formation histories of most small bodies in stellar systems and what the "average" stellar system looks like.
- Balgair 8y ago
  I have close friends working on Psyche! You are right that our understanding of small bodies is going up very quickly, it's quite exciting (in asteroid terms) to be alive now; a lot is being answered and re-questioned with actual evidence. Hopefully (knock on wood) JWST gets up there soon and a LOT more questions can be answered. One issue we have is that there is this 'gap' in planet formation modeling. We can figure out small bodies and large bodies, but things that are ~1m to ~1km in size don't work in the models; they should all just fly apart. Somehow planets do form, but getting there is a pickle, theoretically. Asteroids are likely THE key to understanding that gap, and that should help out with a LOT of system formation dynamics. Also, I'm still bullish on finding a LOT of platinum/gold on asteroids, because space mining. Like, eat your heart out Bruce Willis.
  - InclinedPlane 8y ago
    Awesome! I'm constantly bummed out about the failure of the CONTOUR mission, I can only imagine what we'd know now. Psyche is one of the coolest missions in the pipeline though, it's kind of crazy how fast our knowledge of small bodies is growing.

InclinedPlane 8y ago

Good point. One thing we learned from exoplanet hunting is that there is a much greater diversity out there than we had originally thought, implying that planet formation is a lot more of a dynamic process than our previous models indicated. Prior to the discovery of exoplanets our planet forming models were very much "over fit" to the example of our own Solar System, giving the impression that other stellar systems would end up looking similar to our own. The reality is that our Solar System is, as you say, probably unusual. One aspect of this is that it seems like planetary migrations are pretty common (both inward and outward). If that sort of thing happens early during planet formation then it could easily explain an "asteroid" (which we understand is almost certainly a planetessimal fragment, though many asteroids are just that) which has acquired additional material including ices. The obvious followup here is that we need way, way more closeup observations of small bodies in our own Solar System, we probably also need to develop better techniques for observing interstellar interlopers, and we need to improve our studies of extrasolar planetary systems. Fortunately the first part is already covered, between the Hayabusa 2, Osiris-REX, Lucy, Psyche, and New Horizons missions we should collect a lot more information on such bodies. However, it's probably going to be a long time before we have answers even to simple questions like the formation histories of most small bodies in stellar systems and what the "average" stellar system looks like.

Balgair 8y ago
I have close friends working on Psyche! You are right that our understanding of small bodies is going up very quickly, it's quite exciting (in asteroid terms) to be alive now; a lot is being answered and re-questioned with actual evidence. Hopefully (knock on wood) JWST gets up there soon and a LOT more questions can be answered. One issue we have is that there is this 'gap' in planet formation modeling. We can figure out small bodies and large bodies, but things that are ~1m to ~1km in size don't work in the models; they should all just fly apart. Somehow planets do form, but getting there is a pickle, theoretically. Asteroids are likely THE key to understanding that gap, and that should help out with a LOT of system formation dynamics. Also, I'm still bullish on finding a LOT of platinum/gold on asteroids, because space mining. Like, eat your heart out Bruce Willis.
- InclinedPlane 8y ago
  Awesome! I'm constantly bummed out about the failure of the CONTOUR mission, I can only imagine what we'd know now. Psyche is one of the coolest missions in the pipeline though, it's kind of crazy how fast our knowledge of small bodies is growing.