(Chapter 18)

•
Identify & describe each
Jovian planet
•
Compare and contrast the
Jovian planets
•
Characterize Pluto
Pluto & Charon

What are the basic qualities of Jovian planets?

Jovian planets are often called gas or ice giants.

Contain mostly low density materials

No solid surface

Several moons

Ring systems

Hydrogen rich atmospheres

Practice
What is the most likely method for Jovian planets to have acquired atmosphere? Explain.
a. Outgassing b. Volcanism c. Comets d. Capture

How are Jupiter and Saturn similar?

Deep layers contain liquid and metallic hydrogen

Alternating bands of belts and zones in atmosphere

Strong magnetic fields
Jupiter 20,000x Earth's
Saturn 8,000x Earth's
Jupiter


Rotation Periods average 10 h

Non-solid objects have different rotation speeds at different latitudes.
Differential Rotation

Fluid Spinning Fast Oblate
The smaller the core, the more oblate the shape

Jupiter Saturn

•
Io (P = 1.769 days)
•
Europa (P = 3.551 days)
•
Ganymede (P = 7.154 days)
•
Callisto (P = 16.689 days)

The Great Red Spot on Jupiter is the longest lived weather disturbance in the solar system.

May 15, 2014 NASA

Jupiter’s
Ring

Practice
1) Who was the first person to “see” the
Galilean moons? Why was observing these moons important?
2) Why is it difficult to observe Jupiter’s ring?


Saturn's ring system is divided into 7 major systems.

Each major system is comprised of several ringlets.


Saturn's largest moon,
Titan , has an atmosphere and liquid methane lakes.

Practice
1) How did Saturn get it’s rings?
2) Why would scientists want to explore methane lakes on Titan?

How are Uranus and Neptune similar?

Uranus and Neptune both have methane rich atmospheres.

Uranus looks green-blue

Neptune looks very blue

Uranus
Neptune


Uranus and Neptune both have ring systems.
Uranus’s
Rings
Neptune’s
Rings

 Uranus rotates on its side (90º Tilt), resulting in the most extreme seasons in our solar system.

Neptune’s Spot

Neptune has the strongest winds
(1,200 mph) ever recorded on any planet.
The Great Dark Spot on Neptune
Disappeared in 1994
APOD
May 8, 1996

Practice
1) Why do you think Neptune is more blue than
Uranus?
2) Write a general statement discussing how
Uranus and Neptune compare and contrast with Jupiter and Saturn.

What about Pluto?

Pluto is unlike either
Terrestrial or Jovian planets.
 Orbit is inclined by 17º
 Orbit is elliptical (e = 0.25)
 Composition similar to comet

Pluto is characterized as a dwarf planet.
Pluto before New Horizons

Image Credit: NASA

(2006, International Astronomical Union)
1. Is in orbit around the Sun
2. Has sufficient mass to assume a nearly round shape
3. Is not a satellite (moon)
4. Has cleared the neighborhood around its orbit

Dwarf Planets

Dwarf planets are defined as objects that are similar to planets but do not meet all planet criteria.
Ceres
Pluto
Eris

Practice
1) What criterion is Pluto missing to be classified as a planet?
2) How many moons does Pluto have?

Hubble Finds 'Tenth Planet' Slightly Larger
Than Pluto
04.11.06 NASA

Pluto’s Moons
NASA

Space.com