( ( Lights ( in ( the sky ) ) ) ( ( can ( include ( ( ( such phenomena ) ( as ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ball lightning ) , ) ( swamp gas ) ) , ) ( earthquake lights ) ) , ) meteors ) , ) plasma ) , ) stars ) , ) planets ) , ) ( aircraft lights ) ) , ) ( jet ( or ( rocket exhaust ) ) ) ) , ) sun-dogs ) and ) ( a host ) ) ) ) ( of ( ( other odd ) ( ( ( known or ) unknown ) effects ) ) ) ) ) ) . ) )
(ROOT (S (NP (NP (NNS Lights)) (PP (IN in) (NP (DT the) (NN sky)))) (VP (MD can) (VP (VB include) (NP (NP (JJ such) (NNS phenomena)) (PP (IN as) (NP (NP (NN ball) (NN lightning)) (, ,) (NP (JJ swamp) (NN gas)) (, ,) (NP (NN earthquake) (NNS lights)) (, ,) (NP (NNS meteors)) (, ,) (NP (NN plasma)) (, ,) (NP (NNS stars)) (, ,) (NP (NNS planets)) (, ,) (NP (NN aircraft) (NNS lights)) (, ,) (NP (NN jet) (CC or) (NN rocket) (NNS exhaust)) (, ,) (NP (NNS sun-dogs)) (CC and) (NP (DT a) (NN host)))) (PP (IN of) (NP (ADJP (JJ other) (JJ odd)) (ADJP (VBN known) (CC or) (JJ unknown)) (NNS effects)))))) (. .)))
Lights in the sky can include such phenomena as ball lightning, swamp gas, earthquake lights, meteors, plasma, stars, planets, aircraft lights, jet or rocket exhaust, sun-dogs and a host of other odd known or unknown effects.
(ROOT (S (NP (NNP Plasma)) (VP (VBZ comprises) (NP (NP (NP (DT the) (NN sun)) (CC and) (NP (JJ other) (NNS stars))) (, ,) (CONJP (RB as) (RB well) (IN as)) (NP (NP (NN lightning)) (CC and) (NP (DT the) (JJ northern) (NNS lights))))) (. .)))