( ( Haumea ( is ( ( the ( largest member ) ) ( of ( its ( collisional family ) ) ) ) ) ) ( , ( ( ( a group ) ( of ( ( astronomical objects ) ( with ( similar ( ( ( physical and ) orbital ) characteristics ) ) ) ) ) ) ( ( thought ( to ( have ( formed ( when ( ( a ( larger progenitor ) ) ( was ( shattered ( by ( an impact ) ) ) ) ) ) ) ) ) ) . ) ) ) )
(ROOT (S (S (NP (NNP Haumea)) (VP (VBZ is) (NP (NP (DT the) (JJS largest) (NN member)) (PP (IN of) (NP (PRP$ its) (JJ collisional) (NN family)))))) (, ,) (NP (NP (DT a) (NN group)) (PP (IN of) (NP (NP (JJ astronomical) (NNS objects)) (PP (IN with) (NP (JJ similar) (ADJP (NN physical) (CC and) (JJ orbital)) (NNS characteristics)))))) (VP (VBD thought) (S (VP (TO to) (VP (VB have) (VP (VBN formed) (SBAR (WHADVP (WRB when)) (S (NP (DT a) (JJR larger) (NN progenitor)) (VP (VBD was) (VP (VBN shattered) (PP (IN by) (NP (DT an) (NN impact)))))))))))) (. .)))
Haumea is the largest member of its collisional family, a group of astronomical objects with similar physical and orbital characteristics thought to have formed when a larger progenitor was shattered by an impact.
(ROOT (S (NP (NNP Haumea)) (VP (VBZ is) (NP (NP (NN part)) (PP (IN of) (NP (DT the) (DT a) (JJ collisional) (NN family))))) (. .)))