Transcript Document

Lesson 1
Lesson 1
Original thoughts on the solar
system (and astronomy):
Claudius Ptolemy:
Earth is the center.

He thought that because when you look at the sky at night, you can see all
the stars moving around Earth. Therefore, Earth must be at the center.
Nicolaus Copernicus: The sun is the center of the solar
system.

He thought that because of the observations that he had made.
A group of astronomical (space) objects composed of planets or planetlike stuff revolving around a star.
In our solar system, eight planets revolve around the sun; and one dwarf
planet (Pluto).
Astronomical (space) unit is often used. One AU equals 150 million kilometers
Starting distance in AU
150,000,000
km
AU
km
1 AU
Ending distance in km
*The AU units cancel each other out and you’re left with km.
So, your answer is in km.
150,000,000
AU
1 AU
km
km
Starting distance in AU
150,000,000 km
135
AU
1 AU
20,250,000,000 km
Ending distance in km
Starting distance in AU
150,000,000 km
135
AU
1 AU
20,250,000,000 km
Ending distance in km
You can do the reverse as well…
Starting distance in km
1
AU
km
AU
150,000,000 km
Ending distance in AU
You can do the reverse as well…
Starting distance in km
1
480,000,000
AU
3.2
km
150,000,000 km
Ending distance in AU
AU
Nebular hypothesis:
A cloud of gas and dust in space, known as a nebula, began to rotate. It condensed into a
flattened disk. As the dust and gas condensed, gravity pulled the gas and dust ever closer
together. At the center of the nebula, the particles of gas and dust were pulled so tightly
together that they combined, or fused, together, initiating nuclear fusion . Once nuclear
fusion began, the sun was born.
Solar System Models:
These were created to explain observations of how planets
and other objects in the night sky moved.
The geocentric model put Earth at the center of the solar
system.
The heliocentric model puts the sun at the center of the
solar system.
Claudius Ptolemy: Ptolemy wrote a book that contained the key astronomical
ideas of the time. From about 150 AD, his model dominated scientific thought. He
thought the solar system was geocentric—the planets and sun travel around
Earth in “epicycles,” or large perfectly circular orbits. His model is also known as
the Ptolemaic view of the solar system. Prior to Ptolemy, other ancient
philosophers, such as Aristotle, also suggested the universe was geocentric, but
Ptolemy was the first to explain this model in detail.
Nicolaus Copernicus: Copernicus is considered the father of modern astronomy.
Born in 1543, he used scientific measurements of the planets and stars. He
published a book with the then-controversial idea that Earth was not at the center
of the universe. He provided data and evidence to show that the solar system
was heliocentric. This idea was not very popular in his day because it challenged
the Ptolemaic view which had become the Roman Catholic Church’s official
explanation. To the church, Copernicus’s idea that Earth was not at the center of
the universe was antireligious heresy.
Tycho Brahe: Brahe built one of the first scientific observatories designed solely to
study the sky. He was a diligent note taker and made many calculated observations
of the movement of objects in the universe. He is known as the “man with the
golden nose” because he lost the tip of his nose during a duel and had a brass and
gold nose replacement.
Johannes Kepler: Brahe hired Kepler as an assistant in the late 16th century. After
Brahe’s death, Kepler used the meticulous notes and data gathered by Brahe to
make discoveries about the motion of the planets. Kepler’s work proved
Copernicus’s view that the solar system was heliocentric. Kepler also introduced
the word “satellite” and became the first person to suggest the sun rotates.
Galileo Galilei: Galileo was the first person to scientifically observe rotation of
celestial objects. He constructed one of the earliest telescopes and was the first to
use a telescope to study the night sky. He identified several of Jupiter’s moons by
studying the planet. This led him to suggest that it was like a solar system in
miniature with Jupiter at the center. The church rejected Galileo’s views and
threatened him with death.
Sir Isaac Newton: Newton was a mathematician and philosopher credited with
many discoveries. He was the first to describe gravity and how the planets moved
as a result of gravitational forces. He invented the reflecting telescope, which today
is the main type of telescope used by astronomers. He also discovered that white
light is made up of all colors, enabling astronomers to better understand the
composition of stars.
Practice!
Discover page 2, “Model Development” tab; “check your understanding”
VOCABULARY ALERT!
An object orbiting another object is called a satellite.
The length of time it takes a planet to complete its orbit defines that planet’s
year and is called the revolution rate.
The length of time it takes a planet to complete one rotation defines that
planet’s day and is called the rotation rate.
Kepler’s laws allow you to calculate the shape and duration of a
planet’s orbit.
**Please use the interactive activity on
Discover page 2, “Kepler’s Laws” tab to
help in your understanding of these three
laws.
Kepler’s 1st law tells us: “A
planet travels around the sun
in an elliptical orbit with the
sun at one focus.”
The planet's path is an ellipse (oval/ egg-shaped) with the Sun
at a focus (off-center).
Kepler’s second law states
that the motion of the
planets around the sun
covers the same area in
the same amount of time.
The planet speed changes along the orbit, (it moves slower in the more
distant parts of the orbit). Lines are drawn to the planet
position at equal 1/10 period intervals. These lines are closer together in the
outer part of the orbit since the planet position does
not change as rapidly there.
http://www.physics.sjsu.edu/tomley/Kepler12.html
Kepler’s third law defines
the time it takes a planet to
complete one orbit around
the sun.
The time it takes a planet to make one orbit is called the period (P).
According to the law, the square of the period (or P) equals the
cube of the distance to the planet in AU (or A).
For example, Mars completes one orbital period about every 1.85 Earth years. Mars’
average distance from the sun is about 1.5 AU (or 225 million kilometers).
From these facts, P = 1.85 and A = 1.5.
So Kepler’s third law is correct: 1.85 squared and 1.5 cubed both equal approximately
3.5.
Given the equation P2 = A3, what is the orbital period, in years, for the planet
Saturn? (Saturn is located 9.5 AU from the sun.)
P2?
A = 9.53
Given the equation P2 = A3, what is the orbital period, in years, for the planet
Saturn? (Saturn is located 9.5 AU from the sun.)
P2?
A = 9.53 = 857.375
Given the equation P2 = A3, what is the orbital period, in years, for the planet
Saturn? (Saturn is located 9.5 AU from the sun.)
P2?
A = 9.53 = 857.375
857.375 =
Given the equation P2 = A3, what is the orbital period, in years, for the planet
Saturn? (Saturn is located 9.5 AU from the sun.)
P2?
A = 9.53 = 857.375
857.375 = ~29
P = ~29 years
Given the equation P2 = A3, what is the orbital period, in days, for the planet Mars?
(Mars is located 1.52 AU from the sun?)
P?
A = 1.523
Given the equation P2 = A3, what is the orbital period, in days, for the planet Mars?
(Mars is located 1.52 AU from the sun?)
P?
A = 1.523 = 3.511
Given the equation P2 = A3, what is the orbital period, in days, for the planet Mars?
(Mars is located 1.52 AU from the sun?)
P?
A = 1.523 = 3.511
3.511 =
Given the equation P2 = A3, what is the orbital period, in days, for the planet Mars?
(Mars is located 1.52 AU from the sun?)
P?
A = 1.523 = 3.511
3.511 = 1.83 years
(*we need the answer in days so…)
1.83 years
365 days in a year
Given the equation P2 = A3, what is the orbital period, in days, for the planet Mars?
(Mars is located 1.52 AU from the sun?)
P?
A = 1.523 = 3.511
3.511 = 1.83 years
(*we need the answer in days so…)
1.83 years
P = ~684 days
365 days in a year = 684 days
Lesson 2
Lesson 2
For there to be gravity…
does there need to be air?
GravityA force of attraction between two objects that
depends on two things: mass and distance.
1.) The larger the mass the greater the gravitation attraction.
2.) The closer the two objects the stronger the attraction.
Air resistance is caused by the friction between
a falling object and the particles in air. The
amount of air resistance a falling object
experiences is based on the shape of the object
and the speed at which it falls.
His observations of the movement of objects on
Earth led him to conclude that all objects
accelerate as they fall.
Acceleration is the rate of change in velocity.
When we are talking about the acceleration of a falling
object it would be: “… an increase in speed over time”.
Acceleration of a falling object is due to gravity. All objects fall at a
constant rate, the only reason we see them falling different is due to
other forces acting on the objects.
Positive acceleration can result from an increase in speed. Negative
acceleration, also called deceleration, results from a decrease in speed.
Newton observed that planets moved in an
orbital path around the sun.
NewtoN’s laws of
Motion
• 1st law:
An object in motion will remain in motion,
at a constant velocity, unless an outside force acts
on it. And an object at rest will remain at rest
unless an outside force acts on it.
– Example:
This ball will sit here forever, and
ever, and ever unless something
acts on it; like someone kicks it.
Outside force – a push!
• 2nd law: Force = mass x acceleration
Would the same "force” (push or pull)
be used to move each guy below?
If no, why?
The less mass (the boy) the less force needed for acceleration.
The greater the mass (the sumo wrestler) the more force needed for acceleration.
• 3rd law: For every force (action) there is an equal
and opposite force (reaction).
Raft moves
Diver moves
Equal in speed (acceleration) and opposite in
direction.
Einstein says that time and space are intricately related.
Called the space-time continuum, time and space can be thought
of as a sort of fabric. Objects within time and space will bend this
“fabric,” creating a gravitational force.
Be sure to do the following activity on the
“Discover” page, under the “Einstein in space” tab;
at the bottom.
Earth has a magnetic field, called the
magnetosphere.
Earth’s magnetic field creates a sort of “shell” that protects Earth from
much of the sun’s radiation.
Earth's magnetic field interacts with the radiation from the sun.
Earth’s atmosphere is filled with air molecules.
Ions from the sun collide with the air molecules in Earth’s atmosphere.
The molecules become excited and give off light as they calm down.
Auroras (a.k.a. = Northern/Southern Lights)
Lesson 3
Lesson 3
This is the study of how the sun interacts with the Earth
and the rest of the solar system.
The sun is made of plasma.
Plasma is the fourth state of matter.
It comprises electrons and charged atoms, known as ions.
The sun is made up mostly of hydrogen and some helium gasses.
The sun makes up 99.9 percent of all the matter in the solar system.
(*That means that EVERYTHING else out there is only .1% of
the total mass – so the sun is huge!)
The sun is nearly 110 times wider than Earth. About 1 million Earths
would fit inside the sun.
The surface of the sun has a temperature of about 5,500 degrees Celsius. At the
sun’s core, temperatures are about 15 million degrees Celsius.
Lesson 3 – Discover pg. 1 – “Layers of the Sun” tab.
Please complete the interactive on Discover pg. 1 under the tab
“Solar Energy”:
Nuclear fusion:
When atoms collide (under super high pressure and temperature),
they can be squeezed so tightly that they fuse together.
->This fusion forms new elements.
Nuclear fission:
The opposite happens as well, when atoms split apart.
Earth has a magnetic field, called the
magnetosphere.
Earth’s magnetic field creates a sort of “shell” that protects Earth from
much of the sun’s radiation.
Earth's magnetic field interacts with the radiation from the sun.
Plasma from the sun, known as the solar wind, travels toward Earth.
A solar storm describes any increase in activity on the sun.
MUST complete the following interactive on Discover pg. 2, under
the “Solar Activity” tab.
CME: A coronal mass ejection, (CME), is a bubble of solar-wind gases
shot from the sun’s surface.
Prominence: A loop-shaped plasma ejection formed in the sun’s
atmosphere.
Sunspots: Each sunspot is a location where the magnetism of the sun
creates a cooler region we perceive as a dark “blemish” on the sun’s
photosphere.
(The sunspot is still shining, just not as brightly as the rest of the sun.)
Solar Flares: A sudden explosion of charged particles from the solar
atmosphere.
*This is only ONE part of the assignment, but sure to include all of the
information listed previously.