They probably shouldn't appear in the Alpha sector, and should be more rare overall. Having them as an extremely rare special challenge is fine; having them happen everywhere or randomly occur on a player's first starting planet when they're just learning the game is not fine, because they rapidly lose their novelty and just become an annoyance. And they should be mentioned in the planet view when choosing a planet to beam to.
I don't think that would do anything, though. Meteor showers aren't planet specific, so you would just have every planet saying that ...
