Re: why are they all pointing their lasers at us?
'Morning, sir or madam or neuter,' the alien said. 'This your planet, is it?'
'Well, yes. I suppose so.' he said.
The alien stared thoughtfully at the skyline.
'Had it long, have we, sir?' it said.
'Er. Not personally. I mean, as a species, about half a million years. I think.'
The alien exchanged glances with its colleague. 'Been letting the old acid rain build up, haven't we, sir?' it said. 'Been letting ourselves go a bit with the old hydrocarbons, perhaps?'
'Could you tell me your planet's albedo, sir?' said the the alien, still staring levelly at the horizon as though it was doing something interesting.
'Well, I'm sorry to have to tell you, sir, that your polar ice caps are below regulation size for a planet of this category, sir.'