Had to look up some numbers to see if that's actually feasible and you're right, but catching it would take a long time. If we used a New Horizons-type straight launch at maximum velocity on a Falcon Heavy and a really light probe, it might get there in something like 20 years, well beyond the orbit of Pluto. If BFR was able to launch in 2021 and carry a fat booster-enabled payload, it might be able to get to rendezvous faster. Some interesting charts and explanations available at [1].

[1] https://spectrum.ieee.org/tech-talk/aerospace/space-flight/h...

You don't want to just catch it though, you want to rendevous and spend time alongside/orbiting it.

That could be doable with a Jupiter flyby and close-solar-encounter, but you also want to do it close enough to earth to be able to get meaningful data back, and have enough instrumentation on it to be able to fully explore it (ideally a lander too)

The question is whether or not it will be more or less than 20 years until we encounter another such object.

The Ramans do everything in threes.

Great reference, thank you. I'd forgotten that trait, need to read the book again.

Even if something else comes along, maybe this one was special. It acted very strangely. What if we detect 5 more in the coming century, but none does that interesting "accelerating without pluming" thing?!

Astronomers think we get several inside Earth's orbit each year, and interceptable ones come in on a weekly basis.

Detecting them is the tricky part

with a NERVA powered craft launched on top of something the size of a fully expendable Falcon heavy, maybe...