( ( During ( a ( lunar eclipse ) ) ) ( , ( ( the Earth ) ( ( will ( ( ( ( move directly ) ( between ( ( ( the sun ) and ) ( the moon ) ) ) ) , ) ( causing ( a ( shadow ( to ( fall ( on ( the moon ) ) ) ) ) ) ) ) ) . ) ) ) )
(ROOT (S (PP (IN During) (NP (DT a) (NN lunar) (NN eclipse))) (, ,) (NP (DT the) (NN Earth)) (VP (MD will) (VP (VB move) (ADVP (RB directly)) (PP (IN between) (NP (NP (DT the) (NN sun)) (CC and) (NP (DT the) (NN moon)))) (, ,) (S (VP (VBG causing) (NP (DT a) (NN shadow) (S (VP (TO to) (VP (VB fall) (PP (IN on) (NP (DT the) (NN moon))))))))))) (. .)))
During a lunar eclipse , the Earth  will move directly between the sun and the moon, causing a shadow to fall on the moon.
(ROOT (S (SBAR (WHADVP (WRB When)) (S (NP (NP (NN earth) (POS 's)) (NN shadow)) (VP (VBZ falls) (PP (IN on) (NP (DT the) (NN moon)))))) (, ,) (NP (DT the) (NN shadow)) (VP (VBZ causes) (NP (DT a) (NN lunar) (NN eclipse))) (. .)))
When earth’s shadow falls on the moon, the shadow causes a lunar eclipse.