Uranus, Neptune and Beyond Physics 112 Star Systems Lecture 17 Uranus, Neptune and Beyond Kevin H Knuth University at Albany Fall 2012

The heavens are now seen to resemble a luxuriant garden, which contains the greatest variety of productions, in different flourishing beds. William Herschel Discoverer of Uranus, Mimas, Enceladus, Titania, and Oberon

Comparison of Planetary Sizes http://www.rense.com/general72/size.htm

Comparison of Planetary Interiors http://wapi.isu.edu/Geo_Pgt/Mod11_Jupiter/mod11.htm

Uranus Mass: 8.68 x 1025 kg Diameter: 31,690 km Density: 1.29 gm/cm3 19.2 AU from the Sun Rotation: -17.9 hours Revolution: 84 years “Surface” gravity: 7.77 m/s2 “Surface” Temp: -315° F Atmospheric Composition: 83% H2 15% Helium 2% Methane

Uranus

Uranus’ Rings

Uranus System

Uranus’ Moons Oberon Ophelia Portia Prospero Puck Rosalind Setebos Stephano Sycorax S/1986 U10 S/2001 U2 S/2001 U3 S/2003 U1 S/2003 U2 S/2003 U3 Titania Trinculo Umbriel Ariel Belinda Bianca Caliban Cordelia Cressida Desdemona Juliet Miranda

Uranus’ Moons Miranda Ariel Umbriel Titania Oberon

Neptune Mass: 1.02 x 1026 kg Diameter: 61,400 km Density: 1.64 gm/cm3 30.1 AU from the Sun Rotation: 16.11 hours Revolution: 164.7 years “Surface” Temp: -243° to -405 ° F Atmospheric Composition: 85% H2 13% Helium 2% Methane

Neptune vs. Earth

Neptune

High-Altitude Clouds

Cirrus Clouds on Neptune

Great Dark Spot

Small Dark Spot

Neptune’s Rings Neptune’s rings are almost broken into what we call ring arcs.

Neptune’s Moons Larissa Proteus Naiad Thalassa Triton Nereid S/2002 N1 S/2002 N2 S/2002 N3 S/2002 N4 S/2003 N1 Naiad Thalassa Despina Galatea

Triton Mass: 2.14 x 1022 kg Diameter: 3,354 km Density: 1.29 gm/cm3 “Surface” Temp: -391° F Atmospheric Composition: Nitrogen (tenuous) Coldest known object in the Solar System. Triton is in a retrograde orbit. Due to its orbit and warped shape scientist’s believe that it once was a double planet and was captured by Neptune. Where its partner is is anyone’s guess!

Neptune and Triton

Ice Plain

Cantaloupe Terrain Such terrain has only been seen on Triton. It is probably due to tectonic activity with liquid coming up through the cracks and refreezing.

A Closeup of Triton

Liquid Nitrogen Geysers!!!

Artist’s Conception http://www.arcadiastreet.com/cgvistas/neptune_050.htm

Detection of Triton’s Atmosphere

The Icy Worlds of the Kuiper Belt

Kuiper Belt

Kuiper Belt and Oort Cloud While there are many Kuiper Belt Objects, there collective mass is estimated to be about 1/10 Earth’s mass.

Pluto, Charon and Nix and Hydra

Pluto from HST

Best Image of Pluto

Pluto Comparison

New Horizon’s Mission to Pluto The New Horizons mission is on its way to Pluto. It will make Pluto closest approach on 14 July 2015

View from Eris (formerly Xena) and Dysnomia

View from Sedna