Transcript The Solar System

The Solar
System
Each galaxy is made up
of thousands of solar
systems – collections of
celestial objects that
revolve around one or
more suns.
It is estimated that our
solar system is 5 billion
years old.
It is theorized that a
solar system evolves as
a collection of gas and
dust that combined
forming a sun due to
gravitational attraction.
Once this “new sun”
forms, masses of
gas/dust around the sun
form celestial bodies
(planets) revolving
around the sun.
Components of the Solar System
ASTEROID: Irregular, solid mass
that revolves around the Sun.
MOON: Spherical object that revolves
around a planet or asteroid.
PLANET:
Spherical
objects
that
revolve
around the
Sun
METEOROID: Very tiny solid masses that revolve
around the Sun. If these masses enter Earth’s
atmosphere they are known as METEORS. METEORITES
are the remnants of a meteor found on the Earth’s
surface
COMET: Small, solid masses of
dust/ice that have an orbit
around the Sun.
Characteristics of Planets
RT = Pg.
15
The distance between a planet and the Sun has an effect on the
other characteristics a planet might exhibit.
What patterns can you make between the planets in the Solar System using this
chart?
RT = Pg.
15
Terrestrial Planets
During the formation of the
Solar System, the terrestrial
planets were impacted by the
high temperatures and pressure
from the Sun. Less dense
elements were pushed out of
the inner solar system.
MERCURY
VENUS
Terrestrial Planets:
1. …are closer to the sun.
2. …have small diameters.
3. …have high densities.
4. …have solid surfaces.
5. …have few or no moons.
EARTH
MARS
Jovian Planets
During the formation of the Solar
System, the Jovian planets were not
impacted by the high temperatures and
pressure from the Sun. These planets
are made up of the less dense elements
that were pushed out of the inner solar
system.
JUPITER
Jovian Planets:
1. …are further from the sun.
2. …have large diameters.
3. …have low densities.
4. …have gaseous surfaces.
5. …have many moons.
SATURN
URANUS
NEPTUNE
Planetary Motions
Rotation is the movement of a
planet on an imaginary axis that
runs through it. The time to
complete one full rotation is
known as a day.
The Earth rotates from west to
east.
Revolution is the movement of
a planet on a path (orbit)
around the sun. The period of
time to complete one full
revolution is known as a year.
Planets revolve
counterclockwise around the
sun.
Orbital Shape
A planet’s revolution
around the sun is not in
the form of a perfect
circle, but rather an
oval shape. This
shape is known as an
ellipse.
Each planet’s “elliptical
orbit” is not the same.
Eccentricity is a
measure of the shape
of an orbit around
another celestial object.
Orbits that are “very
eccentric” tend to be
flat and oval. Orbits
that are “less eccentric”
tend to be more
circular.
Eccentricity
Eccentricity is the measurement of the
orbital shape of a celestial body.
RT = Pg. 1
Eccentricity: e = d
L
d = distance between foci
orbit
f1 = the sun
the planet
revolves
around.
f2 = an area in
space along
the major
axis between
the sun and
the orbit.
Orbits that are
“nearly
circular” have
an eccentricity
close to 0
f1
f2
L = length of the major axis
Orbits that are
“very flat and
oval-like” have
an eccentricity
close to1
Eccentricity
Determine the eccentricity of Planet “X”?
Eccentricity: e =
e=
RT = Pg. 1
Eccentricity: e = d
L
d = distance between foci
orbit
Planet
“X”
f1
f2
L = length of the major axis
Orbital Velocity
The revolution of one celestial
object around another (Ex:
planet around a sun) is a
balance between the forces of
inertia and gravity.
Inertia is the property in which
matter remains in a state or rest
or motion, unless an opposing
force acts upon it.
Gravitational force
between Sun and planet
Gravity is the attractive
force between any two
objects in the universe.
Pathway of
inertia
The orbital velocity of a
celestial body is in dynamic
equilibrium – between
inertia and gravity.
Orbital Velocity
Due to the eccentricity of orbits in
the Solar System, the orbital
velocity of a celestial body will
change during its revolution.
In perihelion, the planet is
closest to the Sun in its orbit.
The gravitational force is
greatest between the planet and
the Sun.
The orbital velocity would be
greatest at this time.
In aphelion, the planet is furthest
away from the Sun in its orbit.
The gravitational force is at its
lowest between the planet and
the Sun.
The orbital velocity would be
the slowest at this time.
Orbital Velocity
The further a planet is from the Sun in
the Solar System…
The weaker its gravitational
attraction with the Sun…
The slower its orbital velocity…
The longer its period of revolution…
Ex: Compare the orbital
velocities of Venus and
Mars.
Mars is further from
the Sun than Venus.
Mars has a period of revolution that
is 687 days. Venus has a period of
revolution that is 224.7 days.
Venus has a shorter period of
revolution and is closer to the Sun
than Mars. Thus, Venus has a
greater orbital velocity than Mars.