Transcript Magnetic fields

Journal 10/31/16
Do you think it matters that God gave humans their own
world? Would things be different if instead humanity had
evolved on some nice Earthlike moon going around… say,
Juipiter?
Objective
Tonight’s Homework
To learn about the last outer
planets
Read 13.2, 13.3, and 13.4
(pp 316-321)
Notes on Uranus and Neptune
Properties
The two outermost planets are small and cold.
Both Uranus and Neptune have similar
composition and are only 16 times more
massive than Earth.
Both these planets have less ammonia and more
methane than Jupiter and Saturn. This is what
gives them their blue color.
Notes on Uranus and Neptune
These planets have only a few surprises. The
biggest is that Uranus is tilted on its side by
more than 90 degrees.
This gives it very odd seasons. In “fall” and
“spring”, the planet rotates in the direction it
orbits. This means the side faces the sun.
In “winter” and “summer”,
one pole faces this sun.
This pole gets constant
light, while the other
side of the planet is in
shadow for
decades.
Notes on Uranus and Neptune
Atmospheres
This is where things get
interesting. The outer planets
receive a lot less energy from
the sun. As far as we
understand, all weather on
planets is caused by incoming
solar energy. Therefore,
Uranus and Neptune should
not have weather.
When we look at Neptune,
though, it has weather.
Extreme weather. Winds
easily reach speeds of 1,500
km/hr. Why? We don’t know!
Notes on Uranus and Neptune
Magnetic fields
Another thing we understand poorly about these
planets is their magnetic fields. In the inner
planets, rotating molten metal cores generate
magnetic fields. For the gas giants, it’s believed
the layers of metallic hydrogen do this. Jupiter
and Saturn easily follow this pattern and work.
Uranus and Neptune
do not. Once again,
we do not know why.
Notes on Uranus and Neptune
Moons
Uranus and Neptune both have a large number
of moons, most of which are airless and
composed of ice/rock mix. One interesting
moon, though, is Uranus’ moon Miranda.
While small, this moon
is interesting. The moon
is covered with a mass of
crazy jumbled terrain.
Our best guess is that this
moon fractured from an
impact at one point and
reassembled with the pieces
all broken and rotated.
Notes on Uranus and Neptune
Neptune has one moon of interest, Triton. By
this distance from the sun, most objects are
very cold. Triton is the coldest known body in
the solar system at an average temperature of
35 K.
Temperatures this cold create some very odd
effects. Triton is
volcanically active.
However, the volcanoes
are made of ice and water
rather than rock and lava.
These “cryovolcanoes”
erupt liquid water, which
quickly freezes on the
surface.
Notes on Uranus and Neptune
Rings
The last feature to discuss are the rings of
Uranus and Neptune. Saturn isn’t the only
planet with rings. In fact, Jupiter has rings as
well. However, the rings of the gas giants
besides Saturn are thin and usually broken into
segments. They’re also made of much darker,
dirtier ice that absorbs most light, so they are
hardly visible.
Solar System Travel Brochure
We’re going to start a week-long project today designed
to let you explore the Solar System in more detail.
We’re going to do this by imagining it’s the far future.
Mankind has colonized space and can safely transport
people to other places in the solar system.
Your job is going to be to create a tourist brochure for a
location in the Solar System where you’ve set up a tourist
trap. A point of interest that people would want to pay
money to see or experience.
Let’s talk about how we’re going to make this educational
and gradeable.
Solar System Travel Brochure
Requirements:
1) Choose a place in the Solar System. It can be
anywhere. We’ve discussed lots of places, but there
are plenty others we haven’t.
2) Pick an activity or feature that would be interesting.
EX: Mars  Ski down the slopes of Mount Olympus!
3) Collect scientific information. You need to give the
tourist details about what they may encounter in this
place. Include temperature, gravity, the amount and
type of atmosphere, surface geology, special features,
etc…
4) Facility information. How will your facility operate and
protect people from harsh conditions? Example: If you
build on Venus, come up with some semi-realistic way
you could protect from the heat.
Solar System Travel Brochure
5) Sell the Location. What’s going to be here that’s worth
the money and time of the tourist? With our Mars
example, we would want to add other stuff. Maybe
glider rides from the peak, or an expansive lobby from
which to watch global dust storms when Martian
weather gets nasty. SELL IT. Making something look
appealing is a skill you NEED.
6) Set a price. This only needs to be a little realistic, but I
want to make sure you have a rough idea of the scale
of things it would take to make something like this
realistic. How many visitors would you expect a year /
be able to handle?
Solar System Travel Brochure
So here’s the points breakdown:
1) Location  10%. Pick somewhere interesting!
2) Activities  20%. Show that you know and understand
the appeal of the location. Use it to the fullest.
Essentially, you get points here if you make Mr. C. wish
it was real.
3) Scientific Info  30%. Remember, this is school. Learn
4) Facility Info  20%. Show that you understand both
safety and realism in designing your destination.
5) Sell It  10%. Make everything look good. Art,
presentation, and neatness count here.
6) Price  10%. If your place is too opulent and your
prices way too high, you’ll lose points here. Try to keep
things real.
Your final turn in will be a paper folded into a brochure!
Exit Question
Why do Uranus and Neptune have off-center magnetic
fields?
a) Their cores are off-center
b) The magnetic material is off-center
c) Their rings distort the shape of the field
d) The moons change the center of the field
e) We don’t know
f) None of the above