MR. BANKS GRADE SCIENCE
Transcript of MR. BANKS GRADE SCIENCE
The solar systemMR. BANKS
8TH GRADE SCIENCE
Ancient astronomers
Ancient peoples noticed that most of the stars stayed in
the same position as one another from night to night, they
called these patterns constellations.
Some stars seemed to move from night to night, they
called these wanderers or planetae.
Geocentric universe
The Greeks believed that the universe was a perfect
sphere with Earth at its center.
The geocentric system is the idea that the Earth is at the
center of the revolving planets and stars.
Geocentric universe
Later the geocentric
model was updated to
account for the retrograde
movement of the planets.
This model was accepted
for almost 1,500 years.
Heliocentric universe
Though it wasn’t accepted until the renaissance (1500’s),
another astronomer developed a different model.
In the heliocentric model, the Earth and other planets
revolve around the sun.
Heliocentric universe
Galileo used a telescope to make
discoveries that supported the
heliocentric model.
Moons revolving around Jupiter
Venus’ position near the sun
The sun
Located at the center of
the solar system.
Made of about ¾
hydrogen and ¼ helium.
Makes up 99.8% of the
Solar System’s mass.
The sun is a giant ball of
glowing plasma that’s
constantly undergoing
nuclear fusion.
It’s NOT a gas, it’s NOT
“burning”
The Sun’s interior
The Sun’s core
Where the Sun’s energy is
produced.
The sun produces energy by
nuclear fusion.
In nuclear fusion, small
atoms are joined together
to make larger ones.
Producing energy when
they do.
~15,000,000 °C and under
high pressure (the conditions
needed for fusion)
The Sun’s interior
The radiation zone
Energy produced in the core
slowly moves, mainly in the
form of electromagnetic
waves, outward from the
core of the Sun over the
course of 100,000 years.
The convection zone
Hot gasses rise from the
bottom and cool as they
rise, gradually moving
energy to the surface.
The Sun’s atmosphere
The photosphere
The gasses at the bottom of the Sun’s atmosphere. This is
where the light is released and what we see when we
look at the sun.
The Sun’s atmosphere
The chromosphere
A faint reddish colored
layer that envelops the
Sun and is only visible
during solar eclipses when
the photosphere is
blocked.
The Corona
The faintest and
outermost layer of the
sun. Made up of fast
moving particles that will
spread out and become
the solar wind.
Sunspots
Darkened areas on the surface of the sun
where cooler gasses collect and appear darker
than the other parts of the photosphere.
Solar flares
Magnetically charged
loops of gasses called
prominences extend out
into space near sunspots.
Solar flares happen when
these loops connect and
an explosive release of
magnetic energy propels
superheated gas out into
space.
Solar wind
A stream of high energy
and high speed, charged
particles that originate
from the sun and blast their
way across the solar system
and out into interstellar
space.
The intensity of the wind
can be greatly increased
by solar flares.
We are protected by
Earth’s magnetic field.
They are responsible for the
auroras (northern lights).
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The planets
The inner planets
Mercury, Venus, Earth, and Mars
These are known as the terrestrial planets because they
are small, dense (they don’t have super thick
atmospheres), and have rocky surfaces.
Mercury
The first planet
The smallest “planet” in the
solar system. (it’s barely larger
than Earth’s moon)
Mercury has no moons and
barely any atmosphere.
Due to its closeness to the sun
and lack of atmosphere,
Mercury experiences very
extreme temperatures.
430° C in the day and -170° C
at night
Mercury
Mercury’s surface is covered in craters, showing that there
has been very little geologic activity on the surface for the
last few billion years.
So when something hits Mercury the mark stays.
Venus
The second planet
Venus was once considered to be Earth’s “twin”
It’s about the same size as earth as well as the same density
Venus is the closest planet to Earth.
Venus’ atmosphere
The most prominent
feature of Venus is its thick
atmosphere made up
mostly of carbon dioxide.
Venus is also covered in
thick clouds made of
droplets of sulfuric acid.
The atmosphere is so thick
and heavy that the
pressure from its weight is
90 times that of Earth.
Venus’ atmosphere
Due to the thick
atmosphere, most of the
Sun’s energy is reflected
back off into space.
The energy that does
make it through is
converted into heat which
gets trapped by the
planets greenhouse effect.
Due to this, the
temperature on the
surface is ~460° C.
Venus’ surface
Using radar, probes
have found that
Venus has a rocky
surface with fewer
craters than Mercury
as well as many
large volcanos.
Venus’ surface
Many probes have been sent to Venus.
Only four sent back pictures of the surface.
The longest any of them could survive the harsh
environment was 2 hours and 7 minutes.
Earth
The third planet in the
solar system.
The only known place
that has living things.
Water covers 70% of
the planet’s surface.
It is unique in that it
has water in all three
physical forms. (solid,
liquid, and gas)
Has an atmosphere
that is not too thick or
too thin.
The moon
The moon is Earth’s only
natural satellite.
In ancient times, people
thought that the surface of
the moon was more like
Earth’s.
They thought the dark spots
were oceans, the light spots
mountains, and the craters
volcanos.
The moon is made up of
mostly solid rock.
The moon
We now know that the moon is
made up of mostly rock.
The top layer is a very fine
powder.
There is no atmosphere on the
moon.
There is evidence that water
exists as ice at the poles of the
moon.
Due to the lack of atmosphere,
lunar temperatures vary
greatly from 130° C in the day
to -180 ° C at night.
The moon
The moon is only about 1/50
the size of earth. It is about as
wide as the US.
The other planets in the solar
system could fit in the space
between Earth and the moon.
Origin of the moon
The moon might have formed along with the Earth or it
might have been captured by Earth’s gravity after
forming elsewhere.
The collision hypothesis
About 4.5 billion years ago a planet sized object collided
with Earth. The collison ejected material from earth’s outer
layers into space. The ejected material collected together
in orbit around the earth eventually forming the moon.
Mars
The fourth planet
Reddish in color due to an
abundance of iron rich
rocks on its surface.
Mars
Mars is the most Earth-like
planet in the solar system,
however you wouldn’t want
to live there.
Mars is a little over half the
diameter of earth.
Mars’ atmosphere is very
thin compared to ours, and
is 95% CO2
Temperatures range from
20° C to -130° C.
Mars’ surface
Mars has a rocky
surface that is
reshaped by erosion
from dust storms.
Mars has giant
volcanos on its surface,
however they are no
longer active.
Water on Mars
Today, the only water on Mars
is frozen at the poles.
Scientists think that long ago
before Mars’ core solidified, its
atmosphere was thicker,
temperatures were warmer,
and there was a large amount
of liquid water.
Mars’ moons
Mars has two moons.
Both moons are very small.
Deimos – 15 kilometers in
diameter.
Phobos – 27 kilometers in
diameter.
Phobos has a degrading orbit
and is slowly spiraling in
towards Mars. It’s expected to
crash into the Martian surface
in about 40 million years.
The outer planets
Jupiter, Saturn, Uranus, and Neptune
The outer planets
All four are gas giants, incredibly large, massive planets
that do not have a solid surface, instead they have a
thick atmosphere surrounding a super thick liquid layer
around a small solid core.
Jupiter
The fifth planet
Largest planet in the
solar system.
1,300 Earths could fit
inside Jupiter.
Jupiter alone is 2 ½
times the size of all
the other planets
combined.
Jupiter is mainly made
of hydrogen and
helium (like the sun)
Jupiter’s layers
Jupiter is thought to have 4 primary layers
Hydrogen and helium gas
Liquid-metallic hydrogen and helium
Liquid water and heavier elements
Solid, rocky core
The air/liquid pressure goes up as you go down deeper.
At the core it’s 30 million times the pressure on Earth
The red spot
Jupiter’s “red spot” is a
storm, similar to a
hurricane.
It was first observed in
the 1600’s.
Current observations
show that it is changing
shape and possibly
shrinking.
However, it is still very,
very large.
Jupiter’s moons
Jupiter has 67 known moons
There are four large moons and the rest are
comparatively tiny
Galilean moons
Io, Europa, Ganymede, and
Callisto.
All four are larger than the
dwarf planets and
Ganymede is larger than
Mercury.
Galilean moons
Io – The most geologically
active object in the solar
system, covered in volcanos
and huge mountains.
Callisto – Not as active as the
other large moons, rocky
surface, may have water
deep underground.
Ganymede – Covered in
thick layers of ice, liquid
water may exist sandwiched
between ice layers.
Europa
A rocky moon with a crust
made of ice likely with
liquid water underneath.
Slightly smaller than Earth’s
moon.
Heated from below by an
active core.
Now thought to be the
most likely home of
extraterrestrial life in our
solar system.
Saturn
The sixth planet
Second largest planet in the solar system
It is a gas giant similar to Jupiter
Mostly made of hydrogen and helium
Saturn’s rings
Planetary rings are made of small particles (99.9% ice) of
material individually orbiting the planet.
Saturn’s rings vary from 10 meters to 1 kilometer in thickness.
All the gas giant planets have rings of varying sizes.
Earth
Saturn’s moons
Saturn has 62 known moons
and many small moonlets.
Titan - Saturn’s largest moon,
has a thick atmosphere and a
cycle, similar to Earth’s water
cycle, that occurs with the
compounds methane and
ethane.
Uranus
Pronounced YOOR-uh-nus
The seventh planet in the
solar system.
Its blue-green color
comes from the methane
present in its atmosphere.
However, it’s atmosphere
is mostly hydrogen and
helium.
Uranus rotates on its side.
It is thought that at some
point the planet was hit
by a large object that
caused its odd rotation.
Neptune
The eighth and last
planet.
Like Uranus, Neptune’s
atmosphere is mostly
hydrogen and helium and
its blue color comes from
methane.
Uranus and Neptune are
also similar temperatures,
averaging around -200° C
The “great black spot” is a
storm similar to Jupiter’s.
It reforms and disappears
every few years.
Ice giants
Many scientists want to
reclassify Uranus and
Neptune as “ice giants”
They are only about
20% hydrogen and
helium (vs Saturn and
Jupiter’s >90%)
The majority of each
planet is made up of a
thick layer of “fluid”
ices.
Dwarf planets
Following the discovery of multiple objects similar to Pluto
(and one that was even bigger than Pluto) a new
classification for planets was created.
1. The object must be in orbit around the Sun.
2. The object must be massive enough to be a sphere by its
own gravitational force.
3. It must have cleared the neighborhood around its orbit.
There can’t be any other large objects near the path the “planet” orbits in.
Dwarf planets
There are currently five
confirmed dwarf planets
Pluto, Ceres, Haumea,
Makemake, and Eris
There are an estimated
200 dwarf planets in the
area “near” Pluto, and as
many as 10,000 dwarf
planets orbiting the sun at
extreme distances.
Pluto
The first dwarf planet
discovered.
Pluto is small, about 2/3 the
size of our moon.
We know little about Pluto, it is
likely rocky and very cold.
It has five moons – the largest,
Charon is about 1/10 the size
of Pluto itself.
Pluto
Pluto has a very odd orbit
compared to the other
planets, another reason it
didn’t make sense to
include it as a planet.
New horizons
A space probe launched in 2006 on a mission to
investigate Pluto.
It has also investigated an
asteroid and Jupiter on
the way.
It’s currently 59,000,000 mi
from Pluto.
The dwarf planets
Eris – The largest dwarf
planet, ¼ the size of Earth.
Takes 558 years to orbit the
sun.
Haumea – Has two moons,
observations of telescope
images suggest that
Haumea is an ellipsoid.
Makemake – Not much is
known about it besides that
it is about 2/3 the size of
Pluto.
Ceres The largest object in the
asteroid belt between Mars
and Jupiter.
There are a pair of bright
spots located in a crater,
it’s not clear what they are.
It accounts for 1/3 of the
total mass of the asteroid
belt.
Ceres has a thin dusty outer
layer over a layer of water
ice with a rocky core.
The Dawn space probe
entered into orbit on April
24th and should help gather
more info on Ceres.
Pluto update
Comets
A small object orbiting the sun
in an elliptical orbit.
When it passes close to the sun,
the comet heats up and the
materials that make up the
comet begin to escape out into
space.
The materials are blown away
in the solar wind and from a
stream of visible particles
known as the tail of the comet.
This can include water, carbon
dioxide, methane, ammonia or
even rock dust.
Rosetta
Launched in 2004.
Investigated several asteroids
before achieving successful
orbit around the comet 67P.
Asteroids
Also known as minor planets or planetoids.
Defined as anything above a certain size that isn’t
rounded like a planet and isn’t a comet.
Can range in size from 1,000 km to 10 m.
Generally composed of rock and ice.
Meteors
A small rocky or metallic
object traveling through
space.
They range in size from a
grain of sand to 1 meter
wide.
Most are fragments that
have broken off comets or
asteroids.
Meteors that enter Earth’s
atmosphere are the
“shooting stars” seen at
night.
Meteors
As they fall through the
atmosphere, friction from air
molecules heat the surface of
the meteor and melt/break it
apart.
What lands is only a small
fraction of the original object.
In space they are known as
meteoroids.
When falling through the
atmosphere they are meteors.
And on Earth they are
meteorites.
The asteroid belt A region of space roughly
between Jupiter and Mars
that is occupied by
millions of asteroids.
We’ve identified
hundreds of thousands.
Over 200 are greater
than100 km wide.
Collisions between
asteroids happen
frequently (on an
astronomical time scale)
with large asteroids
colliding about every 10
million years.
The Kuiper belt
Similar to the asteroid belt in that it contains large numbers of “small” objects.
However it is far wider and there are much more massive objects located there.
All the known dwarf planets besides Ceres are located there.
It extends from the orbit of Neptune outward another 1,800,000,000 miles.
The Oort cloud
A theoretical sphere of icy bodies that extends out far away from the Sun, as far as 2 light years.
Studies of comets and their orbits have given rise to the hypothetical existence of this region.
The Oort cloud comprises the theoretical extent of the gravitational influence of the sun.
None of our current probes will reach what is thought the be the outer edge of the cloud before their batteries run out.