Neptune: the Last Giant

Neptune is the 8th planet from the Sun oridinarily. Pluto comes closer to the Sun for a small part of its orbit.

A mathematical prediction by French and English astronomers in 1846 led to the discovery of Neptune within 1 degree of predicted location by the Berlin Observatory on 1846sep23 (No-428).


  1. NASA Goddard Spaceflight Center Neptune site I Good images.
  2. NASA Goddard Spaceflight Center Neptune site II: NSSDC Photo Gallery Saturn Good images.
  3. NASA Planetary Rings site Good images and captions.
  4. Views of the Solar System by Calvin J. Hamilton. A commercial site, but many of the images are pure public domain NASA, but CJH has doctored some images and made them his copyright. Somehow CJH has managed to collect many of the great NASA images that are almost impossible to find on NASA's own side.


  1. ./neptune.jpg Neptune is blue by scattering from methane gas like Uranus.

    But it has more weather and white clouds of methane ice crystals.

    Credit: NASA.

  2. ./neptune_ring_001_arcs.gif Neptune and two of its narrow rings.

    LeVerrier is the inner ring and Adams is the outer one.

    LeVerrier is actually uniform in structure (although it doesn't quite look that way), but Adams shows concentrations of particles that turn up as bright arcs.

    Adams has four arcs of which three are visible in this image: Liberte, Egalite, Fraternite.

    The arcs are probably due to gravitational perturbations of the 150 km diameter moon Galatea (SRJ-229) which is not seen in this image.

    Credit: NASA.