Transcript The Solar System - Rudds Classroom

The Solar
System:
A4: Our Solar System
The sun and inner planets
Our Solar System
• Solar System – a collection of planets, asteroids,
moons, and other matter that occupy the
space around a sun and are held within its
gravitational pull
• Our solar system is located in the Milky Way
galaxy
– Milky Way is a spiral
galaxy with arms and
a central bulge
– Our solar system is
located in one of
the arms
Our Sun
• Our Sun – Has 3
interior layers & 3
atmosphere layers
• Interior Layers
– Core – produces
enormous
amounts of energy
through nuclear
fusion
– During the fusion process, hydrogen atoms
join together to form helium
– Requires temperature of about 15 million oC
Our Sun
– Radiation Zone –
region of tightly
packed gas where
energy is transferred
in the form of
electromagnetic
radiation
– It is the middle layer of the sun
– Because it is so dense, energy can take over
100,000 years to move through it
Our Sun
– Convection Zone –
hot gases rise to the
surface, then sink
back down as they
cool, forming loops
– It is the outer layer of
the sun
– The loops allow energy to move through the
layer
Our Sun
• Atmosphere Layers
– Photosphere – visible
layer (surface) that
gives off light
– Chromosphere –
Very thin middle
layer that produces
the yellow color that we see
– Corona – the halo that surrounds the sun and
extends for millions of kilometers
– Gradually thins to streams of electrically
charges particles called the solar wind
The Planets
• The Planets – Earth is just one of ________
nine? planets
eight
that orbit the sun.
How many planets are there?
Mercury, Venus, Earth, Mars,
Jupiter, Saturn, Uranus, Neptune, Pluto?
Is Pluto a planet? No
• Definition of a Planet
1. It is in orbit around the sun
2. It is nearly round in shape
3. It has cleared the neighborhood in it’s orbit
The Planets
• To remember the order of the planets, just
remember the saying: My Very Excellent Mother
Just Served Us Nachos
• The eight planets of our solar system are:
Mercury, Venus, Earth, Mars, Jupiter, Saturn,
Uranus, and Neptune
• They are divided into two groups of four: the
inner planets and the outer planets
The Inner Planets
• The four inner planets are small, dense, and
have solid rocky surfaces.
• Mercury – smallest planet (about the size of our
moon) and closest to the sun
– Rotates around the sun in 88 days
– Mostly made of dense metal iron
with large plains and craters
– Very little gravity because of its small mass
– Virtually no atmosphere
– Temperatures – as hot as
430o C during the day and
-170o C at night
The Inner Planets
• Venus – has a similar size, mass, and
internal structure to Earth
– Rotates around the sun in 7.5
months, but takes 8 months to
rotate on its axis. So 1 day is
longer than 1 year
– Rotates from east to west
which is opposite to most
planets.
– Astronomers believe it was struck by a large
object that caused it to change its direction
of rotation
The Inner Planets
– Atmosphere is mostly carbon dioxide
with thick clouds of sulfuric acid.
– The carbon dioxide and clouds create a
greenhouse effect trapping heat
– Has the hottest surface temperature of all the
planets at 460o C (hot enough to melt lead)
Mercury & Venus
The Inner Planets
• Earth – Only planet in our solar
system able to support living
organisms
– Rotates around the sun in
365.25 days, and takes 24
hours to rotate on its axis.
– Has 3 main layers: core, mantle, and crust
– Crust is a solid, rocky surface
– Water – it is the only planet with liquid water
– 0ver 70% of surface is covered in water
– Temperatures between -80o C and 70o C
The Inner Planets
– The temperatures allow
water to exist in solid, liquid,
and gas form
– Has enough gravity to hold
together its atmosphere
– Atmosphere: over 100 km thick (about 62 miles)
– Made of oxygen, carbon dioxide, nitrogen,
argon, and other gases
78% _____________________________
Nitrogen
Oxygen
21% _____________________________
Argon
1% ______________________________
Carbon Dioxide
Less than 1% _____________________
The Inner Planets
• Mars – Called the “Red Planet”
due to iron rich rock that covers
the surface
– Rotates around the sun in 687
days, and takes 24 hours 37 min
to rotate on its axis.
– Atmosphere – 95% carbon dioxide, very thin,
with few clouds
– Thin atmosphere allows the surface to be
viewed from Earth with a telescope
– Surface temperatures range from -140o C to
20o C
The Inner Planets
– Water: Images show a variety of
features that appear to have
been made by streams, lakes,
oceans, and coastlines
– Mars had large amounts of liquid water in the
distant past
– Had to have been warmer with a thicker
atmosphere
– Now all the water is frozen, in
the two polar ice caps and
underground
The Inner Planets
– Mars has seasons just like Earth
– Because of the seasons, one
ice cap grows, while the other
shrinks.
– As the seasons change, the process reverses
itself
Mars
In Closing
• Why is it important to learn about the other
planets in our solar system?