My hard-ish SF story requires an event that would effectively render the entire solar system completely uninhabitable for some time (i.e. retreating underground for a few millennia won't help), but without destroying it.
Currently, my main candidate is a fast moving non-pulsar neutron star passing through the system (any other suggestions are welcome). From a story point of view this should make it harder to detect and therefore give us limited time to prepare, ideally a century at most - I know an encounter like this is astronomically unlikely, but as far as I'm aware there's nothing in physics that outright prevents it from happening, i.e. it's hugely improbable but not impossible.
From what I've read elsewhere, such a high mass object racing through the system should drag a swarm of Oort Cloud objects with it resulting in a lot of planetary impacts. However, what I'd like to know is if there would be other destructive effects besides the gravitational in a situation like this. For example:
- If a gas or ice giant and its moons fell into the neutron star, would this release enough radiation to be bad news for the rest of the system or would it just be a pretty light show?
- Given the magnetic fields of neutron stars, would such an encounter have any appreciable effect on solar activity, or would this be purely gravitational?
- Would radio communications be compromised or be unaffected?
I know I've not provided any numbers such as the speed, distance or mass of the neutron star, but that's deliberate as I'm trying to tailor the outcome of this event to the needs of the story while remaining as scientifically accurate as possible (hugely improbable stellar encounter notwithstanding).