Download 07_Jovian planets

What is a planet?
• http://www.youtube.com/watch?v=RQU
2Q-CU6lY
• What is a planet?
1. orbits the sun
2. nearly round shape because its own
gravity is sufficient
3. neighborhood is cleared because its
gravity is sufficient
Copyright © 2010 Pearson Education, Inc.
What is a dwarf planet?
1. orbits the sun
2. nearly round shape because its own
gravity is sufficient
3. neighborhood is not cleared because its
gravity is not sufficient
4. Not a moon of another planet
Copyright © 2010 Pearson Education, Inc.
Chapter 7
The Jovian Planets
Now we shift gears
from our local rock
planets to the outer
gas giants.
We have in our own
solar system 4
examples of each of
the types of planets!
Why is Jupiter so
happy?
Copyright © 2010 Pearson Education, Inc.
Why name planets after
Greek/Roman gods and goddesses?
•
•
•
•
Everything important got a god associated with it.
Why Roman took over Greek names?
What about dozens of other cultures and myths?
Did the Greeks think the god Jupiter was literally
in that speck of light?
• Modern convention in our solar system
• Rules governed by the IAU http://www.iau.org/
Copyright © 2010 Pearson Education, Inc.
Mercury is the god of commerce, travel and thievery in Roman mythology.
The planet probably received this name because it moves so quickly across
the sky.
Venus is the Roman goddess of love and beauty. The planet is aptly named
since it makes a beautiful sight in the sky, with only the Sun and the Moon
being brighter.
Earth is the only planet whose English name does not derive from
Greek/Roman mythology. The name derives from Old English and Germanic.
There are, of course, many other names for our planet in other languages.
Mars is the Roman god of War. The planet probably got this name due to its
red color.
Jupiter was the King of the Gods in Roman mythology, making the name a
good choice for what is by far the largest planet in our solar system.
Saturn is the Roman god of agriculture.
Uranus is the ancient Greek deity of the Heavens, the earliest supreme god.
Neptune, was the Roman god of the Sea. Given the beautiful blue color of
this planet, the name is an excellent choice!
Pluto is the Roman god of the underworld in Roman mythology. Perhaps the
planet received this name because it's so far from the Sun that it is in
perpetual darkness.
Copyright © 2010 Pearson Education, Inc.
The planets in East Asia cultures
For the five true planets, their element's Chinese
character, hanzi(汉字), is also part of the names of
weekdays in Japanese and Korean, complemented
with Sunday and Monday.10 However, Chinese and
Vietnamese number the days other than Sunday.11
The cycles of the Chinese calendar are linked to the
orbit of Jupiter, there being 12 sacred beasts in the
Chinese dodecannualar geomantic and astrological
cycle, and 12 years in the orbit of Jupiter.
Copyright © 2010 Pearson Education, Inc.
Chinese/J
English Associate apanese Chinese Japanese Korean Vietname
Name
d element Character pinyin
romaji
Name
se Name
s
수성
Mercury water
Shuǐxīng Suisei
(Suseong Sao Thủy
水星
)
Sao Kim,
also "Sao
Mai" as
금성
"morning
metal/gol
Venus
Jīnxīng Kinsei
(Geumse star" and
金星
d
ong)
"Sao
Hôm" as
"evening
star"
화성
Mars
fire
Huǒxīng Kasei
(Hwaseo Sao Hỏa
火星
ng)
목성
Jupiter
wood
Mùxīng Mokusei (Mokseo Sao Mộc
木星
ng)
토성
Copyright © 2010 Pearson Education, Inc.
Saturn
earth
Tǔxīng
Dosei
(Toseong Sao Thổ
土星
Old
astronomi
cal
names[12]
Chénxīng
(辰星)
Tàibái (太
白)
Yínghuò (
熒惑)
Suì (歲)
Zhènxīng
Units of Chapter 7
Observations of Jupiter and Saturn
The Discoveries of Uranus and Neptune
Bulk Properties of the Jovian Planets
Jupiter’s Atmosphere
The Atmospheres of the Outer Jovian Worlds
Jovian Interiors
Summary of Chapter 7
Copyright © 2010 Pearson Education, Inc.
Our mission
• Understand the properties of these 4
planets
• Relate their properties to their origin
• Compare them to each other
• Compare them to the rocky inner
planets
• Be able to find Jupiter in the sky, and
see its moons with binocs
Copyright © 2010 Pearson Education, Inc.
7.1 Observations of Jupiter and Saturn
Jupiter can be imaged well from Earth, even
with a small telescope.
Do you have binoculars?
Here: Jupiter with its Galilean moons
Copyright © 2010 Pearson Education, Inc.
19 jan..7.1 Observations of Jupiter and
Saturn
True-color
image of Jupiter
This image is from
Hubble, but much
of our Jupiter
knowledge is from
the Galileo probe
which cost $1.6b
over 16 years
http://www.dailymotion.com/vide
o/xeaio4_learn-about-thediscoveries-of-the_tech
Copyright © 2010 Pearson Education, Inc.
7.1 Observations of Jupiter and Saturn
Natural-color image of Saturn
https://www.youtube.com/watch
?v=AyFMPdHU1n0 stop at
5:50min
Saturn has a thick atmosphere:
why can we see it so clearly?
Copyright © 2010 Pearson Education, Inc.
7.1 Observations of Jupiter and Saturn
Cassini image of
Jupiter, true color
Copyright © 2010 Pearson Education, Inc.
The Cassini mission: Wow!
• Look at nasa site and wikipedia
• Here’s a nice TED talk
http://www.ted.com/talks/carolyn_porco
_flies_us_to_saturn.html
Copyright © 2010 Pearson Education, Inc.
23 Jan: 7.2 The Discoveries of
Uranus and Neptune
Uranus, in natural
color.
Note the absence
of features and
the prevalence of
beauty.
How was Uranus
discovered?
Copyright © 2010 Pearson Education, Inc.
7.2 The Discoveries of Uranus and
Neptune
Neptune in natural
color
How was Neptune
discovered and
how was this
different from every
other planet so far?
Copyright © 2010 Pearson Education, Inc.
7.3 Bulk Properties of the Jovian
Planets
The Jovian planets are large and much less dense than
the terrestrial planets; Saturn is less dense than water!
None have a solid surface at all, although all have a
dense core more massive than earth? explain that!
Copyright © 2010 Pearson Education, Inc.
7.3 Bulk Properties of the Jovian
Planets
Where is
the
snowball
that started
each
planet?
Jovian planets,
compared to
Earth
Copyright © 2010 Pearson Education, Inc.
7.3 Bulk Properties of the Jovian
Planets
Peculiarity of Uranus: Axis of rotation lies
almost in the plane of its orbit. Seasonal
variations are extreme.
Copyright © 2010 Pearson Education, Inc.
Do your research
• In assigned pairs, make a model for all
the jovian planets. Use available
materials. Your model must show or
allow demonstration of:
• Interior structure
• Atmosphere and clouds
• Rings
• Magnetosphere
• Weather
• Differential rotation
Copyright © 2010 Pearson Education, Inc.
Galileo spacecraft
The Galileo spacecraft is the only
one to have entered orbit around
Jupiter, arriving in 1995 and
studying the planet until 2003.
• http://en.wikipedia.org/wiki/Galileo_(spacecraft)
• On September 21, 2003, after 14 years in space and
8 years in the Jovian system, Galileo '​s mission was
terminated by sending the orbiter into Jupiter's
atmosphere at a speed of over 48 kilometers (30 mi)
per second, eliminating the possibility
of contaminating local moons with terrestrial bacteria.
Copyright © 2010 Pearson Education, Inc.
Copyright © 2010 Pearson Education, Inc.
atmosphere
Copyright © 2010 Pearson Education, Inc.
7.4 Jupiter’s Atmosphere
Atmosphere has bright
zones and dark belts.
Zones are cooler, and
are higher than belts.
Simplified model is
shown:
We also see atmospheric
rotation on earth:
http://earth.nullschool.net/
Copyright © 2010 Pearson Education, Inc.
7.4 Jupiter’s Clouds
No solid surface; take
top of troposphere to
be 0 km.
Lowest cloud layer
cannot be seen by
optical telescopes.
Measurements by
Galileo probe show
high wind speeds even
at great depth – probably
due to heating from
planet, not from Sun.
Why this composition?
Copyright © 2010 Pearson Education, Inc.
7.4 Jupiter’s Atmosphere
The Galileo probe
descended into Jupiter’s
atmosphere and returned
valuable data. The arrow
indicates its entry point.
What is difference
between gas
atmosphere and
clouds?
Copyright © 2010 Pearson Education, Inc.
7.4 Jupiter’s Atmosphere
Major visible features:
Bands of clouds; Great Red Spot
Shown
actual
size!
Copyright © 2010 Pearson Education, Inc.
A hurricane
that is
several
hundred
years old,
2x the
diameter of
earth
7.4 Jupiter’s Atmosphere
Two examples of
smaller storms
merging, first into
a smaller red spot,
second into existing
Great Red Spot
Check: write
a weather
forcast for
Jupiter….
Copyright © 2010 Pearson Education, Inc.
7.5 The Atmospheres of the Outer
Jovian Worlds
The atmosphere of Saturn
is similar to that of Jupiter,
except that Saturn is
somewhat colder and its
atmosphere is thicker.
Why is Saturn
colder than
Jupiter? Give
2 reasons……
Copyright © 2010 Pearson Education, Inc.
7.5 The Atmospheres of the Outer
Jovian Worlds
Saturn’s atmosphere
is similar to Jupiter’s,
except pressure is
lower. Why?
It has three cloud
layers.
Cloud layers are
thicker than Jupiter’s;
see only top layer.
Copyright © 2010 Pearson Education, Inc.
7.5 The Atmospheres of the Outer
Jovian Worlds
Saturn also has large storms, and bands.
Copyright © 2010 Pearson Education, Inc.
7.5 The Atmospheres of the Outer
Jovian Worlds
Storms near Saturn’s equator
Evidence of lightning
Copyright © 2010 Pearson Education, Inc.
7.5 The Atmospheres of the Outer
Jovian Worlds
Enormous
thunderstorm on
Saturn
Copyright © 2010 Pearson Education, Inc.
7.5 The Atmospheres of the Outer
Jovian Worlds
Rotation of Uranus can
be measured by
watching storms.
Copyright © 2010 Pearson Education, Inc.
7.5 The Atmospheres of the Outer
Jovian Worlds
Neptune has
storm systems
similar to those on
Jupiter, but fewer.
The large storm
system at top has
disappeared in
recent years.
Copyright © 2010 Pearson Education, Inc.
7.6 Jovian Interiors
No direct information is available about Jupiter’s
interior, but its main components, hydrogen and
helium, are quite well understood. The central
portion is thought to be a rocky core.
Copyright © 2010 Pearson Education, Inc.
Metallic hyrdogen
•
•
•
•
Isn’t hydrogen a gas?
Squeezed between two pieces of diamond, hydrogen has been transformed into a metallic
form believed to exist inside giant planets like Jupiter, scientists reported on Thursday.
“You can see it becomes a lustrous, shiny material, which is what you expect for a metal,”
said Isaac F. Silvera, a professor of physics at Harvard
https://mobile.nytimes.com/2017/01/26/science/solid-metallic-hydrogen-harvardphysicists.html?rref=collection%2Ftimestopic%2FPhysics&action=click&contentCollection=s
cience%C2%AEion=stream&module=stream_unit&version=latest&contentPlacement=1&pgt
ype=collection&_r=0&referer=
Copyright © 2010 Pearson Education, Inc.
7.6 Jovian Interiors
Magnetic fields of Uranus and Neptune must not
be produced by dynamos, as the other planets’
fields are.
Interior structure of Uranus and Neptune,
compared to that of Jupiter and Saturn:
Copyright © 2010 Pearson Education, Inc.
7.6 Jovian Interiors
Jupiter’s
magnetosphere:
Intrinsic field
strength is 20,000
times that of Earth.
Magnetosphere can
extend beyond the
orbit of Saturn.
So catching solar
wind in a magnetic
field should lead
to….?
Copyright © 2010 Pearson Education, Inc.
7.6 Jovian Interiors
Aurorae are seen
on Jupiter, and
have the same
cause as those
on Earth – the
interaction of
solar wind
particles with the
magnetosphere.
Copyright © 2010 Pearson Education, Inc.
7.6 Jovian Interiors
Uranus and Neptune both have substantial
magnetic fields, but at a large angle to their
rotation axes.
The rectangle
within each planet
shows a bar
magnet that would
produce a similar
field. Note that
both Uranus’s and
Neptune’s are
significantly off
center.
Copyright © 2010 Pearson Education, Inc.
Jovians in the news
• P212. a cometary impact
• Why did the comet breakup?
• Did it break up when it went around the
sun?
• Why did it crash into Jupiter?
•
Copyright © 2010 Pearson Education, Inc.
Summary of Chapter 7
• Jupiter and Saturn were known to the
ancients; Uranus was discovered by chance,
and Neptune was predicted from anomalies in
the orbit of Uranus.
• Jovian planets are large but not dense; they
are fluid and display differential rotation.
• Cloud layers have light zones and dark bands;
wind pattern, called zonal flow, is stable.
Copyright © 2010 Pearson Education, Inc.
Summary of Chapter 7, cont.
• Storms appear with regularity; the Great Red
Spot of Jupiter has lasted for hundreds of years
(that we know of).
• Due to conductive interiors and rapid rotation,
Jovian planets have large magnetic fields.
• Jupiter, Saturn, and Neptune radiate more
energy than they receive from the Sun.
Copyright © 2010 Pearson Education, Inc.
A few points in addition to
know.
• Why do they hold gas? Massive,
magnetosphere, and far from sun
• Why are they still losing heat? Still
cooling from the big compression 4+
billion years ago
• Properties of atmospheres? Layers,
clouds, rotation
Copyright © 2010 Pearson Education, Inc.
How are jovians different from
terrestrials to attain their structure?
• Past frost line, snowball and high gravity
early
• Gas was pushed out to them
• Nevertheless, they still collected dust
and debris which is buried under gas
Copyright © 2010 Pearson Education, Inc.
Copyright © 2010 Pearson Education, Inc.
Jupiter as a "cosmic vacuum
cleaner"
http://en.wikipedia.org/wiki/Comet_Shoemaker%E2%80%93Levy_
9
Comet Shoemaker–Levy 9 was a comet that broke apart and
collided with Jupiter in July 1994, providing the first direct
observation of an extraterrestrial collision of Solar System objects.
The impact of SL9 highlighted Jupiter's role as a "cosmic vacuum
cleaner" for the inner Solar System. The planet's strong
gravitational influence leads to many small comets
and asteroids colliding with the planet, and the rate of cometary
impacts on Jupiter is thought to be between 2000 and 8000 times
higher than the rate on Earth.[40] If Jupiter were not present, the
probability of asteroid impacts with the Solar System's inner
planets
would be much greater.
Copyright © 2010 Pearson Education, Inc.
Jupiter as cosmic vacuum cleaner
The extinction of the dinosaurs at the end of
the Cretaceous period is believed to have been caused
by the Cretaceous–Paleogene impact event which
created the Chicxulub crater,[41] demonstrating that
impacts are a serious threat to life on Earth.
Astronomers have speculated that without Jupiter to
mop up potential impactors, extinction events might
have been more frequent on Earth, and complex life
might not have been able to develop.[42] This is part of
the argument used in the Rare Earth hypothesis.
So, thank you Jupiter for protecting us!!!!!
Copyright © 2010 Pearson Education, Inc.
Ode to Jupiter
• https://www.youtube.com/watch?v=3afEX8a2j
Pg 1 min. turn up resolution
• http://www.space.com/29978-nasa-juno-oneyear-jupiter.html and look at video in the
article
• See
https://en.wikipedia.org/wiki/Juno_(spacecraft
)#Planned_deorbit_and_disintegration for
overview
Copyright © 2010 Pearson Education, Inc.
Quiz/activity
1. On full page, draw to best detail you
can the structure of Jupiter, all layers.
2. Then…
3. flip the page, and use book/notes to do
this again, with even better detail.
Copyright © 2010 Pearson Education, Inc.