( ( ( ( ( ( Impressive volcanoes ) ( are ( known ( on mars ) ) ) ) , ) and ) ( there ( may ( ( be ( more ( volcanoes ( on Venus ) ) ) ) ( than ( on ( ( any ( other planet ) ) ( in ( the ( solar system ) ) ) ) ) ) ) ) ) ) . )
(ROOT (S (S (NP (JJ Impressive) (NNS volcanoes)) (VP (VBP are) (VP (VBN known) (PP (IN on) (NP (NNS mars)))))) (, ,) (CC and) (S (NP (EX there)) (VP (MD may) (VP (VB be) (ADJP (RBR more) (JJ volcanoes) (PP (IN on) (NP (NNP Venus)))) (PP (IN than) (IN on) (NP (NP (DT any) (JJ other) (NN planet)) (PP (IN in) (NP (DT the) (JJ solar) (NN system)))))))) (. .)))
Impressive volcanoes are known on mars, and there may be more volcanoes on Venus than on any other planet in the solar system.
(ROOT (S (NP (NNP Venus)) (VP (VBZ has) (NP (DT the) (JJS most) (NNS volcanoes))) (. .)))