( ( Lunar ( Eclipse ( A ( Lunar eclipse ) ) ) ) ( ( occurs ( when ( ( the moon ) ( passes ( into ( ( the ( Earth 's ) ) shadow ) ) ) ) ) ) . ) )
(ROOT (S (NP (NNP Lunar) (NNP Eclipse) (NNP A) (NNP Lunar) (NNP eclipse)) (VP (VBZ occurs) (SBAR (WHADVP (WRB when)) (S (NP (DT the) (NN moon)) (VP (VBZ passes) (PP (IN into) (NP (NP (DT the) (NN Earth) (POS 's)) (NN shadow))))))) (. .)))
Lunar Eclipse A Lunar eclipse occurs when the moon passes into the Earth's shadow.
(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.