( These ( ( ions ( ( ( remove electrons ) ( from ( ( the atoms ) ( in ( ( the ( gaseous envelope ) ) ( of ( the comet ) ) ) ) ) ) ) ( when ( ( the latter ) ( collide ( with ( one another ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (DT These)) (VP (VBZ ions) (VP (VB remove) (NP (NNS electrons)) (PP (IN from) (NP (NP (DT the) (NNS atoms)) (PP (IN in) (NP (NP (DT the) (JJ gaseous) (NN envelope)) (PP (IN of) (NP (DT the) (NN comet))))))) (SBAR (WHADVP (WRB when)) (S (NP (DT the) (NN latter)) (VP (VBP collide) (PP (IN with) (NP (CD one) (DT another)))))))) (. .)))
These ions remove electrons from the atoms in the gaseous envelope of the comet when the latter collide with one another.
(ROOT (S (SBAR (WHADVP (WRB When)) (S (NP (NNS electrons)) (VP (VBP move) (PP (IN from) (NP (CD one) (NN atom))) (PP (TO to) (NP (DT another)))))) (, ,) (NP (PRP they)) (VP (VBP become) (NP (NNS ions))) (. .)))