Japan's priceless asteroid Ryugu sample got 'rapidly colonized' by Earth bacteria

You know what this means? We can give killer asteroids MEASLES when they fly too close.

meanwhile on ISS, 'whats that smell?'

Paging anticolonialist.

The compromise would be to create a signature biome and allow it to contaminate. And if they find some rock which doesn't have that signature biome, then it's probably extraterrestrial.