Topic: Earth rocked by double space impact

[Simon]

We've all seen the films where an asteroid hurtles towards our planet, threatening civilisation.

What's less well known is that menacing space rocks sometimes come in twos.

Researchers have outlined some of the best evidence yet for a double space impact, where an asteroid and its moon apparently struck Earth in tandem.

http://www.bbc.co.uk/news/science-environment-26172181

[daveeb]

Not sure we'd be much better off being hit by one massive asteroid than a massive one with a secondary one in tow 

[Clive]

Before I was born!   

[Simon]

Not often you can say that!   

[Clive]

Geological time-scales are my best friend.