6 ms·

There were a number of anomalous characteristics including its shape, acceleration, rotation, origin, and reflectivity.

ceejayoz 1y ago
How do we know they're anomalous characteristics if it's literally the first one we've ever spotted? What is the normal shape of an interstellar comet core?
- cubefox 1y ago
  For example, being flat like a pancake is obviously highly unusual and very different from anything we have seen from stellar comets.
  - ceejayoz 1y ago
    Stellar comets haven't been ejected from another solar system. We have vanishingly few examples of those, and we've not directly observed any up close. "Flat as a pancake" is one of several theoretical possibilities from its light curve, not a known fact about the object. "Highly unusual" in space tends to mean "there are a bunch, but we haven't seen them until now". In 1992, exoplanets were "highly unusual". Now they're everywhere.
    - cubefox 1y ago
      The highly unusual properties are such that they are genuinely hard to explain for astronomers. See my neighbouring comment.
    - Sharlin 1y ago
      Yes, and the exoplanets we found first were highly unusual and not at all what we expected to find, which triggered tons of new research to amend our models of planetary system formation and dynamics. I’m not even sure what you’re trying to argue here – we found an object that did not fit our model of what things should look like, which is very curious and calls for an explanation. That’s how science works. Doesn’t mean it’s aliens. But “oh well maybe it’s just how things are back where it’s from” does not satisfy anyone.
      - ceejayoz 1y ago
        I think we are actually in agreement. I’m very onboard with “it was an interesting object and we should learn more”. I object to UFO cranks jumping to “it was a starship” conclusions like Avi Loeb wants to. Just as I would have when those weird first exoplanets showed up.
        cubefox 1y ago
        I object to calling Avi Loeb a "crank" just because he thinks it might be an UFO.
        ceejayoz 1y ago
        I object to not calling him a crank. The rest of the scientific community seems to take the same position.
        zikzak 1y ago
        Did he conclude it was a starship or argue we shouldn't dismiss out of hand that an object like this has a non-zero chance of being an artifact of another civilization?
        ceejayoz 1y ago
        I mean, he titled his book about it “Extraterrestrial: The First Sign of Intelligent Life Beyond Earth”. https://en.wikipedia.org/wiki/Extraterrestrial:_The_First_Sign_of_Intelligent_Life_Beyond_Earth https://en.wikipedia.org/wiki/Extraterrestrial:_The_First_Si...
        zikzak 1y ago
        Did he say it was definitely a starship?
        ceejayoz 1y ago
        Will no one rid me of this turbulent priest?
- TheBlight 1y ago
  The same as the ones from this system. Borisov had the same characteristics.
  - ceejayoz 1y ago
    > The same as the ones from this system. Why would we assume non-interstellar comets are always the same as interstellar comets? Conditions obviously are a little different when something is ejected from a system and then spends millions of years in interstellar space. > Borisov had the same characteristics. We have a sample size of three thus far. Making conclusions right now is like saying all extrasolar planets are large gas giants because the first three were.
    - TheBlight 1y ago
      We'd assume most interstellar objects are comets because that's which objects you find on the outskirts of a solar system and are the easiest to get kicked out. We'd assume they're mostly like our comets due to the Copernican principle. We shouldn't assume we're special.
      - ceejayoz 1y ago
        > We'd assume they're mostly like our comets due to the Copernican principle. We're still figuring out what our comets are like, let alone unusual ones spending a few million years in interstellar space. New types of comets(ish) bodies discovered in the 2000s: https://en.wikipedia.org/wiki/Active_asteroid https://en.wikipedia.org/wiki/Active_asteroid https://en.wikipedia.org/wiki/Manx_comet https://en.wikipedia.org/wiki/Manx_comet We've spotted ~5k out of an estimated trillion. Each one we've sent a probe to has brought surprises. The Oort cloud remains theoretical at this time, and the first Kuiper belt object other than Pluto/Charon was found in 1992. It would be deeply silly to think we know everything about our local comets, let alone unusual ones from elsewhere.
    - deleted 1y ago
      [deleted]

How do we know they're anomalous characteristics if it's literally the first one we've ever spotted? What is the normal shape of an interstellar comet core?

cubefox 1y ago
For example, being flat like a pancake is obviously highly unusual and very different from anything we have seen from stellar comets.
- ceejayoz 1y ago
  Stellar comets haven't been ejected from another solar system. We have vanishingly few examples of those, and we've not directly observed any up close. "Flat as a pancake" is one of several theoretical possibilities from its light curve, not a known fact about the object. "Highly unusual" in space tends to mean "there are a bunch, but we haven't seen them until now". In 1992, exoplanets were "highly unusual". Now they're everywhere.
  - cubefox 1y ago
    The highly unusual properties are such that they are genuinely hard to explain for astronomers. See my neighbouring comment.
  - Sharlin 1y ago
    Yes, and the exoplanets we found first were highly unusual and not at all what we expected to find, which triggered tons of new research to amend our models of planetary system formation and dynamics. I’m not even sure what you’re trying to argue here – we found an object that did not fit our model of what things should look like, which is very curious and calls for an explanation. That’s how science works. Doesn’t mean it’s aliens. But “oh well maybe it’s just how things are back where it’s from” does not satisfy anyone.
    - ceejayoz 1y ago
      I think we are actually in agreement. I’m very onboard with “it was an interesting object and we should learn more”. I object to UFO cranks jumping to “it was a starship” conclusions like Avi Loeb wants to. Just as I would have when those weird first exoplanets showed up.
      - cubefox 1y ago
        I object to calling Avi Loeb a "crank" just because he thinks it might be an UFO.
        ceejayoz 1y ago
        I object to not calling him a crank. The rest of the scientific community seems to take the same position.
      - zikzak 1y ago
        Did he conclude it was a starship or argue we shouldn't dismiss out of hand that an object like this has a non-zero chance of being an artifact of another civilization?
        ceejayoz 1y ago
        I mean, he titled his book about it “Extraterrestrial: The First Sign of Intelligent Life Beyond Earth”. https://en.wikipedia.org/wiki/Extraterrestrial:_The_First_Sign_of_Intelligent_Life_Beyond_Earth https://en.wikipedia.org/wiki/Extraterrestrial:_The_First_Si...
        zikzak 1y ago
        Did he say it was definitely a starship?
        ceejayoz 1y ago
        Will no one rid me of this turbulent priest?
TheBlight 1y ago
The same as the ones from this system. Borisov had the same characteristics.
- ceejayoz 1y ago
  > The same as the ones from this system. Why would we assume non-interstellar comets are always the same as interstellar comets? Conditions obviously are a little different when something is ejected from a system and then spends millions of years in interstellar space. > Borisov had the same characteristics. We have a sample size of three thus far. Making conclusions right now is like saying all extrasolar planets are large gas giants because the first three were.
  - TheBlight 1y ago
    We'd assume most interstellar objects are comets because that's which objects you find on the outskirts of a solar system and are the easiest to get kicked out. We'd assume they're mostly like our comets due to the Copernican principle. We shouldn't assume we're special.
    - ceejayoz 1y ago
      > We'd assume they're mostly like our comets due to the Copernican principle. We're still figuring out what our comets are like, let alone unusual ones spending a few million years in interstellar space. New types of comets(ish) bodies discovered in the 2000s: https://en.wikipedia.org/wiki/Active_asteroid https://en.wikipedia.org/wiki/Active_asteroid https://en.wikipedia.org/wiki/Manx_comet https://en.wikipedia.org/wiki/Manx_comet We've spotted ~5k out of an estimated trillion. Each one we've sent a probe to has brought surprises. The Oort cloud remains theoretical at this time, and the first Kuiper belt object other than Pluto/Charon was found in 1992. It would be deeply silly to think we know everything about our local comets, let alone unusual ones from elsewhere.
  - deleted 1y ago
    [deleted]