( ( Although ( methane ( is absent ) ) ) ( , ( ( ( the ( planet 's ) ) atmosphere ) ( ( contains ( both ( water ( and ( carbon monoxide ) ) ) ) ) ; ) ) ) )
(ROOT (S (SBAR (IN Although) (S (NP (NN methane)) (VP (VBZ is) (ADJP (JJ absent))))) (, ,) (NP (NP (DT the) (NN planet) (POS 's)) (NN atmosphere)) (VP (VBZ contains) (NP (DT both) (NN water) (CC and) (NN carbon) (NN monoxide))) (: ;)))
Although methane is absent, the planet's atmosphere contains both water and carbon monoxide;
(ROOT (S (SBAR (IN Although) (S (NP (PRP they)) (VP (VBP differ) (ADVP (RB vastly)) (PP (IN in) (NP (NNS hardness)))))) (, ,) (NP (NP (NN pencil) (NN lead)) (CC and) (NP (NNS diamonds))) (DT both) (VP (VBP contain) (NP (NN carbon))) (. .)))