4 ms·

There will be more like that, but we need to get better at identifying them. Just like with exoplanets.

pavel_lishin 2y ago
Not just identifying them, but also being able to catch them in time. They're coming in at solar escape velocities, and going out with same - and the odds of everything being aligned in such a way that we can take several years to do gravity assists are incredibly low.
- mathsmath 2y ago
  I wonder if a one-way trip with an impactor would be useful. It would at least be easier than a roundtrip journey to and from solar escape velocity. Also, it seems like the space base weapons treaty is being ignored now (https://spacenews.com/russia-vetoes-u-n-resolution-on-nuclear-weapons-in-space/ https://spacenews.com/russia-vetoes-u-n-resolution-on-nuclea..., https://www.npr.org/2024/05/30/nx-s1-4975741/what-to-know-russia-satellite-space-weapon-cosmos-2576 https://www.npr.org/2024/05/30/nx-s1-4975741/what-to-know-ru...). I wonder if there is an opportunity to do some science with space-based lasers and spectroscopy. The energy would be small, but then again we can learn a lot just from the off-gassing created by the sun’s photons as well.
  - pavel_lishin 2y ago
    Oh yeah, I don't think we're anywhere near "sample return" capability for an extra-solar object. I doubt we're even near "impactor" capability, tbh. I think our best bet might be "catch up with something in the Oort somewhere around 2070, if we see something coming a decade ahead of time".
    - mathsmath 2y ago
      Never underestimate the ability of humans to throw something really hard ;) I actually think if the object was on the right trajectory and we had enough time, that you could pretty much park an impactor in its path. You could probably do a lot of science based on the spectra of the resulting cloud. I agree that gently landing and return a sample with that much delta V is out of our reach at this point. Maybe with enough shielding, you could park a second sample return vehicle in the path of debris.
- adolph 2y ago
  > odds of everything being aligned in such a way that we can take several years to do gravity assists are incredibly low. Project Lyra develops concepts for reaching interstellar objects such as 1I / 'Oumuamua and 2I / Borisov with a spacecraft, based on near-term technologies. [0] Several technology options are outlined, ranging from a close solar Oberth Maneuver using chemical propulsion, and the more advanced options of solar and laser sails. [1] 0. https://i4is.org/what-we-do/technical/project-lyra/ https://i4is.org/what-we-do/technical/project-lyra/ 1. https://arxiv.org/abs/1711.03155 https://arxiv.org/abs/1711.03155
  - XorNot 2y ago
    It occurs to me since survivability isn't a problem for an unmanned probe, that a "cold" nuclear thermal engine vehicle could be used as a loitering interceptor: get it a solar orbit, and leave it till you see a target, then accelerate up to extra-solar escape velocity. It solves the disposal problem neatly, since the probe and reactor are both leaving the solar system forever afterwards.

Not just identifying them, but also being able to catch them in time. They're coming in at solar escape velocities, and going out with same - and the odds of everything being aligned in such a way that we can take several years to do gravity assists are incredibly low.

mathsmath 2y ago
I wonder if a one-way trip with an impactor would be useful. It would at least be easier than a roundtrip journey to and from solar escape velocity. Also, it seems like the space base weapons treaty is being ignored now (https://spacenews.com/russia-vetoes-u-n-resolution-on-nuclear-weapons-in-space/ https://spacenews.com/russia-vetoes-u-n-resolution-on-nuclea..., https://www.npr.org/2024/05/30/nx-s1-4975741/what-to-know-russia-satellite-space-weapon-cosmos-2576 https://www.npr.org/2024/05/30/nx-s1-4975741/what-to-know-ru...). I wonder if there is an opportunity to do some science with space-based lasers and spectroscopy. The energy would be small, but then again we can learn a lot just from the off-gassing created by the sun’s photons as well.
- pavel_lishin 2y ago
  Oh yeah, I don't think we're anywhere near "sample return" capability for an extra-solar object. I doubt we're even near "impactor" capability, tbh. I think our best bet might be "catch up with something in the Oort somewhere around 2070, if we see something coming a decade ahead of time".
  - mathsmath 2y ago
    Never underestimate the ability of humans to throw something really hard ;) I actually think if the object was on the right trajectory and we had enough time, that you could pretty much park an impactor in its path. You could probably do a lot of science based on the spectra of the resulting cloud. I agree that gently landing and return a sample with that much delta V is out of our reach at this point. Maybe with enough shielding, you could park a second sample return vehicle in the path of debris.
adolph 2y ago
> odds of everything being aligned in such a way that we can take several years to do gravity assists are incredibly low. Project Lyra develops concepts for reaching interstellar objects such as 1I / 'Oumuamua and 2I / Borisov with a spacecraft, based on near-term technologies. [0] Several technology options are outlined, ranging from a close solar Oberth Maneuver using chemical propulsion, and the more advanced options of solar and laser sails. [1] 0. https://i4is.org/what-we-do/technical/project-lyra/ https://i4is.org/what-we-do/technical/project-lyra/ 1. https://arxiv.org/abs/1711.03155 https://arxiv.org/abs/1711.03155
- XorNot 2y ago
  It occurs to me since survivability isn't a problem for an unmanned probe, that a "cold" nuclear thermal engine vehicle could be used as a loitering interceptor: get it a solar orbit, and leave it till you see a target, then accelerate up to extra-solar escape velocity. It solves the disposal problem neatly, since the probe and reactor are both leaving the solar system forever afterwards.