at some point
the sun ignites
 
planetesimals collect bodies
            outward from the sun
 
earth the third
of accumulation
 
            the moon formed by an off-center blow
 
                                    rocky mantle gathering up
                                    back into earth
                                    and into moon
 
4.5 billion years ago
more or less
 
            biopoesis
 
            meteorite bombardment
 
come the atmosphere
come the oceans