Neptune_Notes

Weather on Neptune

• Warmer than Uranus in upper atmosphere.

• Internal heat escapes and is trapped by atmosphere.

• Thinner haze allows visibility of clouds that are less dense.

• Emits 2.7 times more energy than it receives, theorized due to methane insulation.

• Possible hot south pole.

Discovery by Voyager 2

• Discovered white clouds composed of methane, located about 50 km above other clouds.

• Equatorial winds travel at 200 km/h and exhibit retrograde motion (backwards).

Notable Features

• Great Dark Spot

  • Similar to the Great Red Spot on Jupiter.

  • Can disappear and reappear in different locations; reasons unknown.

Interior Structure

• Similar to Uranus:

  • Core, slushy hydrogen mantle, hydrogen atmosphere.

• Electromagnetic field due to slushy hydrogen acting as metal when spinning.

• Higher density than Saturn and Jupiter suggests a rocky core about 10 times the size of Earth.

• Magnetic field stronger than Earth's but weaker than Jupiter's.

Rings and Moons

• Rings

  • Four dark rings:

    • Three narrow, one broad/diffuse ring.

    • Outer rings show clumping; possibly attributed to shepherd satellites.

• Moons

  • Total of 13 moons; one medium moon.

  • Triton:

    • Largest moon, half the size of Europa, termed the "cantaloupe moon."

    • Exhibits retrograde motion (clockwise orbit).

    • Thin atmosphere with nitrogen geysers; likely a captured Kuiper Belt object slightly larger than Pluto.

    • Icy surface with a surface temperature of 37 K.

Orbital Influence

• Neptune influences Uranus’ orbit through gravitational pull.

• John Adams & Urbain Leverrier calculated Neptune's mass and orbit;

• Discovered by Johann Galle in the night sky.

Atmospheric Composition

• Atmosphere similar to Uranus:

  • Composed of 84% Hydrogen, 14% Helium, and 2% Methane.

  • Methane provides the blue color indicative of Neptune.

Visibility and Observation

• Neptune cannot be seen with the naked eye due to its distance; a telescope is required.

• Appears as a small bluish disk with a few cloud bands, which are visible white clouds.

• Knowledge primarily sourced from Voyager 2, which identified more bands and spots.

Surface Characteristics of Triton (Moon of Neptune)

• Surface features:

  • Nitrogen frost layer with pink areas and few craters.

  • Presence of frozen ice lakes with volcanic origins.

• Expected to approach Neptune in approximately 100 million years and could break apart.