Download Chapter 2 Sec 1 The Sun

Chapter 2 Sec 2 The Sun
I.
Sun’s makeup
a. Contains 99.8% of all mass in solar system
b. Is all gas
i. 3/4 Hydrogen, 1/4 helium, trace
amounts of others
II.
Sun’s interior
a. Energy comes from fusion
i. Hydrogen atom fuse together to form
helium
ii. Requires extremely high temperature
and pressure
iii. Some of the hydrogen mass gets
converted to energy
b. Enough hydrogen left to last 5 billion
years
III. Sun’s atmosphere
a. Photosphere
i. The layer where light is produced
ii. What you see when you see the sun
b. Chromosphere
i. Reddish region in the middle of the
atmosphere
c. Corona
i. Extremely faint, outermost layer
ii. Source of the solar winds (streams of
particles that create the northern
lights).
IV.
Features on the sun
a. Sun rotates on its axis, just like Earth
b. Sunspots
i. Can be as big as Earth
ii. Are cooler than surrounding gas
iii. Varies over 10 or 11 year cycles, which
may cause short-term changes in
Earth’s climate
c. Prominences
i. Loops linking sunspots
d. Solar flares
i. When several loops connect,
temperature may jump up, causing
hydrogen gas to explode
ii. Can greatly increase solar wind
iii. Resulting magnetic storms can
interfere with communications on
Earth.
Ch. 2 Section 3 The inner planets
I.
Terrestrial planets are small and have rocky
surfaces
II. Earth
a. Atmosphere is 100 km (62 miles) thick.
i. Nearly all nitrogen
ii. 20% oxygen
iii. small amounts of carbon dioxide
b. 70% of surface is covered in water
c. Inner core (solid) of iron & nickel
d. One reason to study Earth is to make
inferences about other planets
III. Mercury
a. Closest to the sun, the size of our moon
b. Interior is iron and nickel
c. All information about the surface came from
Mariner 10. Showed flat plains and craters.
d. Very small atmosphere left. Gases got so hot
they escaped into space
e. Temperature range from 450 degree
centigrade to -170 degrees C
IV. Venus
a. Called the evening star or morning star
b. Takes 7.5 Earth months to revolve and 8 Earth
months to rotate, so its day is longer than its
year.
i. Rotates east to west, opposite of most
other planets
V.
ii. Called retrograde rotation
iii. Make have results from a huge collision
c. Extremely thick atmosphere, never has a sunny
day
d. Weighs 90X Earth’s atmosphere, so it would
crush you.
e. Mostly carbon dioxide; clouds are sulfuric acid.
f. Clouds keep all the sun light in, so temperature
is 460 degrees C, hot enough to melt lead
i. Called the greenhouse effect, since that’s
just what greenhouses do. Same reason we
are worried about putting too much carbon
dioxide in our atmosphere
g. 19 spacecrafts; none with humans
i. Magellan took radar pictures, so we know
what the surface looks like
Mars
a. The red planet
b. Very thin atmospheres, mostly carbon dioxide
i. Enough atmosphere to have dust storms
c. Idea about canals on Mars has no validity
i. There is a little bit of water, some frozen
at poles
ii. May also be some under surface – see
formations that look like water has melted
and flowed down the sides of valleys.
d. Axis is tilted so it has seasons like Earth
e. Many spacecraft sent to explore. Coolest had a
small buggy that traveled around the surface
f. Has 2 moons
i. Phobos only 27 km (17miles) across
ii. Deimos only 15 km (9 miles) across
iii. Both are cratered like our moon.
Ch.2 Sec 4 The outer planets
I.
Structure of the gas giants
a. Much larger than Earth and made mostly
of gas
b. Atmospheres
i. Are very deep because the planets’
gravity is so great – gasses cannot
escape
c. Solid cores
i. May be much bigger than Earth, but
has been impossible to find out much
yet because buries so deep
ii. May be rock, ice, frozen carbon
dioxide
II.
Jupiter
a. 300 X the mass of Earth
b. Atmosphere
i. Mostly hydrogen and helium
ii. Great Red Spot is hundreds of time
size of Earth; may be like a hurricane
c. Moons
i. Io, Europa, Ganymede, & Callisto are
the largest. There are 13 others.
ii. Io is very volcanic. Sulfur gives color
to surface
iii. Europa may be covered in a frozen
ocean
iv. Ganymede is 2X our moon; has icy,
cratered surface
v. Callisto is totally cratered.
III. Saturn
a. Second largest planet
b. Only planet less dense than water
c. Rings
i. Chunks of ice and rock
ii. Are thin and flat; can’t see when on
edge
d. Moons
i. Titan is bigger than our moon.
Atmosphere is so thick that we can’t
see the surface
ii. Has 4 other moons
IV.
Uranus
a. 4X the size of Earth
b. Twice as far from the sun as Saturn
c. Bluish atmosphere because has methane
gas
d. Discovery was in 1781
e. Exploring
i. Voyager 2 sent back only close-up
images
ii. Day lasts 17 hours
iii. Axis is off by 90 degrees; caused by
being hit in distant past
f. Moons
i. Total of 17 (Voyager 2 found 10)
V.
Neptune
a. 30X as far away as Earth
b. Discovery
i. Mathematical prediction told
astronomers where to look. Uranus’
orbit was off a little bit, so they knew
something else was out there
c. Exploring
i. Voyager 2 went by here also.
ii. Has clouds and storms
d. Moons
i. 8 moons
ii. Triton has an ice cap with lava (?)
erupting underneath
VI.
Pluto & Charon
a. Are terrestrial, like Earth
b. Very small – Pluto is only 2/3 the size of
our moon
c. Charon is more than 1/2 the size of Pluto,
so more like a double planet
d. Their year is 249 of our years.
e. Discovery
i. Again, because something was
affecting another planet’s orbit
f. Really a planet?
i. Very controversial
ii. Too small
iii. Many other, similar bodies in the
Kuyper Belt.
Ch. 2 Sec 5 Comets, asteroids, and meteors
I.
Comets
a. Dirty snowball, size of Earth mountain
b. Chunks of ice & dust
c. orbits are narrow ellipses
d. When close to sun, ice turns to gas and
releases dust
e. Solid core is the nucleus
f. Gasses around the head are the coma
g. Coma and nucleus together are the head
h. Tail streams out behind
i. solar wind pushes tail out to the side
ii. can be 100s of millions of km long
II.
Asteroids
a. Rocks too small to be considered planets
b. Orbit the sun between Mars and Jupiter,
called the Asteroid Belt
c. Have identified over 10,000
d. Have hit Earth in the past
III. Meteors
a. Meteoroid is a chunk of rock or dust in
space
i. might be from a broken up comet
b. When meteoroid hit our atmosphere,
friction heats it up and you see light in the
sky, which is called a meteor
c. If the meteor hits the Earth it is called a
meteorite
Ch. 2 Sec 6 Is there like beyond Earth?
I.
The “Goldilocks Conditions”
a. Characteristics of living things
i. Made of one or more cells
ii. Take in energy and use it to grow
iii. Reproduce
iv. Give off waste
b. Life as we know it needs:
i. liquid water
ii. suitable temperature range
iii. atmosphere
c. Earth is only place where we know all 3
conditions exist
i. Only a little hotter and all water
would be a gas; little colder and would
all be ice.
II.
Life on Earth
a. We have “extremophile”, meaning things
that love extreme conditions.
i. Some where it is so dark that cannot
use sunlight – they get energy from
chemicals instead
ii. Some where water is very close to
boiling
iii. Some even in nuclear reactors
III. Life on Mars
a. Once did have water on the surface, can
tell from landforms
b. Viking Missions
i. Had labs to look for life – no signs
were found
c. Meteoroids from Mars
i. What looks like fossils in rocks from
Mars cause some to think that life did
once exist on Mars; other scientists
strongly disagree
IV.
Life on Europa?
a. Very likely a liquid ocean of water, so
could be life.
b. Scientists very concerned that any probe
might contaminate it with bacteria or
virus from Earth.