( Tamm ( ( is ( a ( shallow ( lunar ( impact crater ) ) ) ) ) . ) )
(ROOT (S (NP (NNP Tamm)) (VP (VBZ is) (NP (DT a) (JJ shallow) (NN lunar) (NN impact) (NN crater))) (. .)))
Tamm is a shallow lunar impact crater.
(ROOT (S (NP (DT The) (NN lunar) (NN landscape)) (VP (VBZ is) (VP (VBN covered) (PP (IN by) (NP (NP (NNS craters)) (VP (VBN caused) (PP (IN by) (NP (JJ asteroid) (NNS impacts)))))))) (. .)))