Twelve years after launch Voyager approaches its last port of call in the Solar System the planet Neptune in this artwork by Julian Baum Targeted for a flyby of the planets north pole on Aug Voyager will then descend sharply to rendezvous with the Neptunes giant moon Triton Neptune is the fourth largest planet in the Solar System and the outermost of the four great gas giants Its atmosphere consists mainly of hydrogen and helium but visual observations reveal a faint bluish tinge which may indicate the presence of a thick cloud layer which scatters blue light in much the same way as Earths atmosphere does
