>I think it's more likely that an alien probe - assuming there are aliens and they fly probes - would be the size of a cubesat

Or maybe the size of a sub-atomic particle, as in the sci-fi Novel 'The 3 body problem'.

https://three-body-problem.fandom.com/wiki/Sophons

Does anyone else see a timer ticking down in their vision or is it just me?

Time to quit my job at the LHC and be a baker.