( ( ( ( Let ( one ( ( ( ( go ( around ( the other ) ) ) , ) first ) ( without ( any rotation ) ) ) ) ) and ) ( then ( letting ( ( the ( `` ( Moon '' ) ) ) ( rotate ( just ( once ( ( on ( ( its axis ) ( for ( every time ) ) ) ) ( it ( goes ( around ( the ( `` ( Earth '' ) ) ) ) ) ) ) ) ) ) ) ) ) ) . )
(ROOT (S (S (VP (VB Let) (S (NP (PRP one)) (VP (VB go) (PP (IN around) (NP (DT the) (JJ other))) (, ,) (ADVP (RB first)) (PP (IN without) (NP (DT any) (NN rotation))))))) (CC and) (S (ADVP (RB then)) (VP (VBG letting) (S (NP (DT the) (`` ``) (NNP Moon) ('' '')) (VP (VB rotate) (SBAR (RB just) (IN once) (S (PP (IN on) (NP (NP (PRP$ its) (NNS axis)) (PP (IN for) (NP (DT every) (NN time))))) (NP (PRP it)) (VP (VBZ goes) (PP (IN around) (NP (DT the) (`` ``) (NNP Earth) ('' '')))))))))) (. .)))
Let one go around the other, first without any rotation and then letting the "Moon" rotate just once on its axis for every time it goes around the "Earth".
(ROOT (S (NP (NNP Earth)) (VP (VBZ rotates) (PP (PP (IN on) (NP (PRP$ its) (NNS axis)) (ADVP (RB once))) (CC times) (PP (IN in) (NP (CD one) (NN day))))) (. .)))