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Here is the random astronomer on Reddit claiming that the community didn't rule out that it is an abandoned spaceship yet: https://amp.reddit.com/r/space/commen

Here is the random astronomer on Reddit claiming that the community didn't rule out that it is an abandoned spaceship yet: https://amp.reddit.com/r/space/comments/7ealls/solar_systems_first_interstellar_visitor_with_its/ https://amp.reddit.com/r/space/comments/7ealls/solar_systems... "Astronomer here! I will never say this lightly, but we are, swear to God, actually discussing with some seriousness right now what are the odds that this was actually a spaceship. Which I 100% assure you has never happened before in my memory with seriousness."

erikb 9y ago
Why the hack do you assume it's abandoned? It can be full of lifeforms even and we are just not able to see them, talk to them, etc. Imo at this point any assumption is closing in too much. We don't have a definiton of "life" that for sure would include extraterrestrial lifeforms that are not actors with masks in star trek, right?
- paulmd 9y ago
  Well, it's tumbling end-over-end which suggests that if it's a spaceship, it's no longer in control. The discussion around the possibility of it being a spaceship rests on the idea that long thin cigar-shaped objects are the most efficient way to travel in space because it minimizes your need for ablative protection from interstellar dust/etc. But if you're tumbling end-over-end you've thrown that advantage away, so presumably that's not a thing you would intentionally do. And if you are assuming that this spaceship has shields or whatever, then there is no reason they would be restricted to a cylindrical shape. It could be a discarded booster stage or fuel tank, of course. Maybe they were trying to drop it into the sun and missed. Or a a mass-driver shot (maybe they finally took care of that pesky Russell's Teapot for us...) The presumptive conclusion is of course that it's a natural phenomenon, but it sure is a weird object, and unless we can find a way to catch it (or any future objects) we will never know. Maybe a starshot probe could catch it?
  - deleted 9y ago
    [deleted]
  - lawlessone 9y ago
    How is it tumbling? Could that provide a force to simulate gravity?
  - tfha 9y ago
    Wouldn't tumbling a spaceship give you some basic gravity? Isn't that a desired outcome?
    - valuearb 9y ago
      It appears to be tumbling end over end. It's possible that it's spinning end over end in order to generate artificial gravity at the ends, but this contradicts one basic design star-ship design principle. You build a long narrow ship so you can have heaviest particle shielding only at the narrow front to reduce shielding mass required. But maybe since it's traveling so slow, they didn't need any excessive shielding. Maybe they have super light super strong shielding technologies. That itself would seem to be contradictory, given you'd think they'd have access to far more energy than would produce only 40 km/sec velocity.
  - semi-extrinsic 9y ago
    The really interesting prospect raised in that Reddit thread is that while the velocity is likely wrong for an interstellar spaceship, it could be just right for the spent and discarded deceleration stage of an interstellar spaceship. In which case the spaceship would be arriving some time later...
    - cjsuk 9y ago
      I like this explanation best, as long as they're friendly.
    - api 9y ago
      Watch some rocket separations. Usually they end up tumbling.
- zodPod 9y ago
  This has always been my argument too! I understand that scientists want to start with what they know to narrow stuff down but is it not entirely possible that there's life on a planet that just doesn't work like ours? Obviously the organic structures that we're familiar with need a certain series of parameters to survive but that doesn't mean that any other kind of object couldn't end up being a sentient being.
valuearb 9y ago
It’s really traveling far too slowly to be a viable interstellar transport.
- i_am_nomad 9y ago
  What does “viable” mean, though? For us, it might not be viable, but for organisms that live on a different (or even variable) time scale it might be just fine.
  - valuearb 9y ago
    I loved Rendezvous with Rama, and one of it's central lessons is anything is possible when you talk about alien civilizations. We can't assume to know their motivations and technologies. But looking at the basic physics/engineering involved, if it's an alien vehicle it raises some interesting questions and skepticism. Imagine we wanted to build a similar vehicle. If we wanted to send people to nearby stars, we'd likely need vehicles as big, or likely larger, than Oumuamua. If we were in a hurry to do it with present day technologies we'd have to build hundreds of SLS boosters to launch payloads so that astronauts could assemble a vehicle weighing tens of thousands of tons in orbit. And then we'd fuel it with tens of thousand of tons of fuel. So we could build it. What would we use for propulsion? Not chemical rockets, 40KM/sec is only achievable for tiny payloads to fuel ratios with chemical rockets. Maybe we could do it with Nuclear rockets, which were tested and proven to be twice as efficient in the 1960s, ala NERVA. Even then we'd only be able to use a bit more than half the fuel to accelerate towards our destination, if we wanted to stop there. So 40 km/sec would be extremely difficult to reach given how heavy it would be. And at 40 km/sec it would take 8,000 years, nearly a hundred generations before reaching the nearest star. Assuming the life support systems could last that long, they didn't run out of food, water, air, etc. That the engines weren't degraded by radiation over 8,000 years so they would still work when reaching the target. It's extremely unlikely we could count on any of this being true. But if we were ever to launch such a vehicle it would likely be outclassed very quickly. We already know how to build better propulsion systems. Existing ion drives are far more efficient, and theoretically offer over 100KM/sec speeds, we just haven't been able to scale them up yet. If we can scale up ion drives or similar technologies, we already have designs for Project Orion are entirely feasible, and offer massive speed increases. Freeman Dyson's interstellar designs offer 1,000-10,000 KM/sec speeds. If it took us a hundred years to build one, it would likely pass a hundred year old NERVA ship within a year or two. My point is we'd never launch such a slow vehicle as Oumuamua, because it would be relatively easy to build a significantly faster one. Even with todays technologies. So it's reasonable to think that an Alien civilization that could build a ship the size and speed of Oumuamua, could build much larger, faster ships for interstellar travel. If Oumuamua is a ship, the question would be why didn't they? One possible answer if Oumuamua is artificial, that it's not an interstellar vehicle. It's an interplanetary vehicle that had a complete failure of it's systems, and had just enough velocity to leave it's star system, and has been drifting for tens of thousands of years. But in that were the case, how did it came so close to our Sun? It's reasonable to assume that many billions or trillions of asteroids and comets have been ejected by star systems, so that occasionally a few come close enough to ours to make the tight orbit around the Sun that Oumuamua did. But it's hard to imagine there are billions or trillions of space wrecks wandering the milky way such that one randomly passes this close to our sun.
dguaraglia 9y ago
"Rendezvous with Rama" theorized such an incident. Shame we spent too much of the last century blowing each other to smithereens rather than developing the technology to figure it out for sure.
api 9y ago
Well hey... It's possible. Not likely but possible. It could be a dormant long term hibernation ship en route somewhere. Computing it's trajectory would be a way to look at this. Very long term deep hibernation would be one very plausible way to go to the stars. It could also be a ship that malfunctioned and died millions or even billions of years ago. If it were traveling very fast it could play stellar gravity ping pong for a long time until eventually settling into an orbit, hitting something, or being ejected from the galaxy. Picture some insectoid alien mummies playing silent vigil in cold intergalactic space until the heat death of the universe and bust out the theramin. Whatever it is I wish NASA could cook up a flyby. A light small prove could probably get tossed on a high enough energy trajectory to catch it and take some pics. Surely the first extrasolar object is interesting. Edit: elsewhere several people pointed out that a tumbling object like this might not be an interstellar ship/probe but a spent expendable acceleration stage for one.
- valuearb 9y ago
  If it's a spent stage, then the parent vehicle is also traveling very close to 26 KM/sec and is already here.
  - api 9y ago
    ... or arrived a while ago? There could be many acceleration and deceleration stages.

erikb 9y ago

Why the hack do you assume it's abandoned? It can be full of lifeforms even and we are just not able to see them, talk to them, etc. Imo at this point any assumption is closing in too much. We don't have a definiton of "life" that for sure would include extraterrestrial lifeforms that are not actors with masks in star trek, right?

paulmd 9y ago
Well, it's tumbling end-over-end which suggests that if it's a spaceship, it's no longer in control. The discussion around the possibility of it being a spaceship rests on the idea that long thin cigar-shaped objects are the most efficient way to travel in space because it minimizes your need for ablative protection from interstellar dust/etc. But if you're tumbling end-over-end you've thrown that advantage away, so presumably that's not a thing you would intentionally do. And if you are assuming that this spaceship has shields or whatever, then there is no reason they would be restricted to a cylindrical shape. It could be a discarded booster stage or fuel tank, of course. Maybe they were trying to drop it into the sun and missed. Or a a mass-driver shot (maybe they finally took care of that pesky Russell's Teapot for us...) The presumptive conclusion is of course that it's a natural phenomenon, but it sure is a weird object, and unless we can find a way to catch it (or any future objects) we will never know. Maybe a starshot probe could catch it?
- deleted 9y ago
  [deleted]
- lawlessone 9y ago
  How is it tumbling? Could that provide a force to simulate gravity?
- tfha 9y ago
  Wouldn't tumbling a spaceship give you some basic gravity? Isn't that a desired outcome?
  - valuearb 9y ago
    It appears to be tumbling end over end. It's possible that it's spinning end over end in order to generate artificial gravity at the ends, but this contradicts one basic design star-ship design principle. You build a long narrow ship so you can have heaviest particle shielding only at the narrow front to reduce shielding mass required. But maybe since it's traveling so slow, they didn't need any excessive shielding. Maybe they have super light super strong shielding technologies. That itself would seem to be contradictory, given you'd think they'd have access to far more energy than would produce only 40 km/sec velocity.
- semi-extrinsic 9y ago
  The really interesting prospect raised in that Reddit thread is that while the velocity is likely wrong for an interstellar spaceship, it could be just right for the spent and discarded deceleration stage of an interstellar spaceship. In which case the spaceship would be arriving some time later...
  - cjsuk 9y ago
    I like this explanation best, as long as they're friendly.
  - api 9y ago
    Watch some rocket separations. Usually they end up tumbling.
zodPod 9y ago
This has always been my argument too! I understand that scientists want to start with what they know to narrow stuff down but is it not entirely possible that there's life on a planet that just doesn't work like ours? Obviously the organic structures that we're familiar with need a certain series of parameters to survive but that doesn't mean that any other kind of object couldn't end up being a sentient being.

valuearb 9y ago

It’s really traveling far too slowly to be a viable interstellar transport.

i_am_nomad 9y ago
What does “viable” mean, though? For us, it might not be viable, but for organisms that live on a different (or even variable) time scale it might be just fine.
- valuearb 9y ago
  I loved Rendezvous with Rama, and one of it's central lessons is anything is possible when you talk about alien civilizations. We can't assume to know their motivations and technologies. But looking at the basic physics/engineering involved, if it's an alien vehicle it raises some interesting questions and skepticism. Imagine we wanted to build a similar vehicle. If we wanted to send people to nearby stars, we'd likely need vehicles as big, or likely larger, than Oumuamua. If we were in a hurry to do it with present day technologies we'd have to build hundreds of SLS boosters to launch payloads so that astronauts could assemble a vehicle weighing tens of thousands of tons in orbit. And then we'd fuel it with tens of thousand of tons of fuel. So we could build it. What would we use for propulsion? Not chemical rockets, 40KM/sec is only achievable for tiny payloads to fuel ratios with chemical rockets. Maybe we could do it with Nuclear rockets, which were tested and proven to be twice as efficient in the 1960s, ala NERVA. Even then we'd only be able to use a bit more than half the fuel to accelerate towards our destination, if we wanted to stop there. So 40 km/sec would be extremely difficult to reach given how heavy it would be. And at 40 km/sec it would take 8,000 years, nearly a hundred generations before reaching the nearest star. Assuming the life support systems could last that long, they didn't run out of food, water, air, etc. That the engines weren't degraded by radiation over 8,000 years so they would still work when reaching the target. It's extremely unlikely we could count on any of this being true. But if we were ever to launch such a vehicle it would likely be outclassed very quickly. We already know how to build better propulsion systems. Existing ion drives are far more efficient, and theoretically offer over 100KM/sec speeds, we just haven't been able to scale them up yet. If we can scale up ion drives or similar technologies, we already have designs for Project Orion are entirely feasible, and offer massive speed increases. Freeman Dyson's interstellar designs offer 1,000-10,000 KM/sec speeds. If it took us a hundred years to build one, it would likely pass a hundred year old NERVA ship within a year or two. My point is we'd never launch such a slow vehicle as Oumuamua, because it would be relatively easy to build a significantly faster one. Even with todays technologies. So it's reasonable to think that an Alien civilization that could build a ship the size and speed of Oumuamua, could build much larger, faster ships for interstellar travel. If Oumuamua is a ship, the question would be why didn't they? One possible answer if Oumuamua is artificial, that it's not an interstellar vehicle. It's an interplanetary vehicle that had a complete failure of it's systems, and had just enough velocity to leave it's star system, and has been drifting for tens of thousands of years. But in that were the case, how did it came so close to our Sun? It's reasonable to assume that many billions or trillions of asteroids and comets have been ejected by star systems, so that occasionally a few come close enough to ours to make the tight orbit around the Sun that Oumuamua did. But it's hard to imagine there are billions or trillions of space wrecks wandering the milky way such that one randomly passes this close to our sun.

dguaraglia 9y ago

"Rendezvous with Rama" theorized such an incident. Shame we spent too much of the last century blowing each other to smithereens rather than developing the technology to figure it out for sure.

api 9y ago

Well hey... It's possible. Not likely but possible. It could be a dormant long term hibernation ship en route somewhere. Computing it's trajectory would be a way to look at this. Very long term deep hibernation would be one very plausible way to go to the stars. It could also be a ship that malfunctioned and died millions or even billions of years ago. If it were traveling very fast it could play stellar gravity ping pong for a long time until eventually settling into an orbit, hitting something, or being ejected from the galaxy. Picture some insectoid alien mummies playing silent vigil in cold intergalactic space until the heat death of the universe and bust out the theramin. Whatever it is I wish NASA could cook up a flyby. A light small prove could probably get tossed on a high enough energy trajectory to catch it and take some pics. Surely the first extrasolar object is interesting. Edit: elsewhere several people pointed out that a tumbling object like this might not be an interstellar ship/probe but a spent expendable acceleration stage for one.

valuearb 9y ago
If it's a spent stage, then the parent vehicle is also traveling very close to 26 KM/sec and is already here.
- api 9y ago
  ... or arrived a while ago? There could be many acceleration and deceleration stages.