Bell work
Every planet that has an atmosphere has
weather. Jupiter's Great Red Spot appears to be
very similar to a hurricane system on Earth, but it
has lasted for centuries, driven by the planet's
internal thermal energy.
 Write a humorous but accurate weather forecast
for one of the outer planets that has an
atmosphere. Write your report in your science
journal, but be prepared to present it to the
class.

Outer planets
Jupiter, Saturn, Uranus, Neptune
Objectives for today!
Explain
how gas giants are different
from terrestrial planets.
Describe
the individual characteristics
of Jupiter, Saturn, Uranus, Neptune,
and Pluto.
Jupiter




Distance from sun43.3 light-minutes
Period of rotation9 h, 54 min
Period of revolution11 years, 313 days
Temperature−110°C
oGravity-236% of Earth's
Jupiter
Jupiter is the largest planet in our solar system.
 Like the sun, Jupiter is made mostly of hydrogen
and helium.
 The outer part of Jupiter's atmosphere is made of
layered clouds of water, methane, and ammonia.
 At a depth of about 10,000 km into Jupiter's
atmosphere, the pressure is high enough to
change hydrogen gas into a liquid. Deeper still, the
pressure changes the liquid hydrogen into a liquid,
metallic state.

Jupiter
Unlike most planets, Jupiter radiates
much more energy into space than it
receives from the sun. The reason is
that Jupiter's interior is very hot.
 Another striking feature of Jupiter is
the Great Red Spot, a storm system
that is more than 400 years old and is
about 3 times the diameter of Earth!

Distance from sun
1.3 light-hours
 Period of rotation 10
h, 42 min
 Period of revolution
29 years, 155 days
 Diameter 120,536
km
 Temperature
−140°C
 Gravity 92% of
Earth's

Saturn
Saturn
Saturn is the second-largest planet in the solar
system.
 Saturn has roughly 764 times the volume of
Earth and is 95 times more massive than
Earth.
 Its overall composition, like Jupiter's, is mostly
hydrogen and helium. But methane, ammonia,
and ethane are found in the upper
atmosphere.
 Saturn's interior is probably much like Jupiter's.

Saturn
Also, like Jupiter, Saturn gives off much more energy
than it receives from the sun. Scientists think that
Saturn's extra energy comes from helium falling out of
the atmosphere and sinking to the core. In other
words, Saturn is still forming!
 Although all of the gas giants have
rings, Saturn's rings are the largest.
Saturn's rings have a total diameter
of 272,000 km. Yet, Saturn's rings
are only a few hundred meters thick.
The rings are made of icy particles
that range in size from a few
centimeters to several meters wide.

Objectives for today!
Explain
how gas giants are different
from terrestrial planets.
Describe
the individual characteristics
of Jupiter, Saturn, Uranus, Neptune,
and Pluto.
Uranus
Distance from sun 2.7 lighthours
 Period of rotation 17 h, 12
min (R)
 Period of revolution *83
years, 273 days
 Diameter 51,118 km
 Temperature −195°C
 Gravity 89% of Earth‘s

Uranus
Uranus was discovered by the English
amateur astronomer William Herschel in 1781.
 The atmosphere of Uranus is mainly hydrogen
and methane. Because these gases absorb
the red part of sunlight very strongly, Uranus
appears blue-green in color.
 Uranus and Neptune have much less mass
than Jupiter, but their densities are similar.
This suggests that their compositions are
different from Jupiter's. They may have lower
percentages of light elements and a greater
percentage of water.

Uranus
A Tilted Planet
 Unlike most other planets, Uranus is tipped over on its
side. So, its axis of rotation is tilted by almost 90° and lies
almost in the plane of its orbit.

For part of a Uranus year, one pole points toward the sun
while the other pole is in darkness. At the other end of
Uranus's orbit, the poles are reversed. Some scientists think
that early in its history, Uranus may have been hit by a
massive object that tipped the planet over.
Neptune
Distance from sun 4.2 lighthours
 Period of rotation 16 h, 6 min
 Period of revolution163 years,
263 days
 Diameter 49,528 km
 Temperature −200°C
 Gravity 112% of Earth's

Neptune

Irregularities in the orbit of Uranus suggested to
early astronomers that there must be another
planet beyond it.
They
thought that the
gravity of this new planet
pulled Uranus off its
predicted path. By using
the predictions of the new
planet's orbit, astronomers
discovered the planet
Neptune in 1846.
Neptune
The Atmosphere of Neptune



The Voyager 2 spacecraft sent back images that provided
much new information about Neptune's atmosphere.
Although the composition of Neptune's atmosphere is similar to
that of Uranus's atmosphere, Neptune's atmosphere has belts
of clouds that are much more visible. At the time of Voyager 2's
visit, Neptune had a Great Dark Spot like the Great Red Spot
on Jupiter.
And like the interiors of Jupiter and Saturn, Neptune's interior
releases thermal energy to its outer layers. This release of
energy helps the warm gases rise and the cool gases sink,
which sets up the wind patterns in the atmosphere that create
the belts of clouds. Voyager 2 images also revealed that
Neptune has a set of very narrow rings.
Objectives for today!
Explain
how gas giants are different
from terrestrial planets.
Describe
the individual characteristics
of Jupiter, Saturn, Uranus, Neptune,
and Pluto.