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ESS1A, The Universe & the Stars
Learning Target #1
(Performance Expectation #1)
I can develop and use a model of the Earth-sun-moon system to describe cyclic (a cycle that occurs over and over) patterns of lunar phases.
a) I can identify and explain the phases of the moon
Explain how many days it takes for a moon to go through one cycle
…such as how long it would take for a new moon or full moon to occur during the next
cycle
b) I can identify the moon’s cycle in relationship to a month on Earth (full moon, new moon) using diagrams
What causes of the phases of the moon?
The changing relative positions of the moon, Earth, and sun
- As the moon circles the Earth, the shape of the moon appears to change; this is because different amounts of the illuminated part of the moon are facing us. The shape varies from a full moon (when the Earth is between the sun and the moon) to a new moon (when the moon is between the sun and the Earth).
Why is a day and a year on the moon the same length?
The moon rotates once on its axis in the same amount of times as it revolves around Earth.
Also, the same side of the moon always faces Earth
The length of the moon’s day is shorter than the 29.5 days between consecutive full moons
What is the relationship of the Earth and the Moon?
The moon orbits the Earth
Why does the moon not produce light?
Does not produce light, it reflects light from the sun
What are the phases of the moon?
a) The different shapes of the moon you see from Earth (changes in Moon’s visibility)
b) The whole (entire) set of phases that a moon goes through represents one complete revolution around Earth
c) The phase of the moon we see depends on how much of the sunlit side of the moon faces Earth
What is each phase of the moon?
a) New Moon
The side with sunlight faces away from Earth making it appear completely dark (no light anywhere)
29.5 days after the last new moon, the cycle is complete, and a new moon begins
Moon is on same side of Earth as the Sun
b) Waxing Crescent Moon (the light is growing)
c) First Quarter Moon (the light is growing)
d) Waxing Gibbous Moon (the light is growing)
d) Full Moon (happens about once every month)
e) Waning Gibbous Moon (the light is shrinking)
f) Third Quarter Moon (the light is shrinking)
e) Waning Crescent Moon (the light is shrinking)
What is the name of each full moon?
January Moon After Yule, Wolf Moon, or Old Moon
February Snow Moon or Hunger Moon
March Sap Moon, Crow Moon, or Lenten Moon
April Grass Moon or Egg Moon
May Milk Moon or Planting Moon
June Rose Moon, Flower Moon, or Strawberry Moon
July Thunder Moon or Hay Moon
August Grain Moon or Green Corn Moon
September Fruit Moon or Harvest Moon
October Harvest Moon or Hunter's Moon
November Hunter's Moon, Frosty Moon, or Beaver Moon
December Moon Before Yule or Long Night Moon.
Does the moon rise and set each day?
The moon rises and sets every day, appearing on the horizon just like the sun. The time depends on the phase of the moon. It rises about 30 to 70 minutes later each day than the previous day, so the moon is out during daytime as often is it's out at night.
Position at a full moon of Earth, moon, and sun
Position at a new moon of Earth, moon, and sun
The full moon doesn't occur on the same day of every month because the moon takes 29½ days, and not specifically a month, to orbit the Earth. (As a result of this, you get to witness two full moons in a single calendar month every three years.) On the day of the full moon, it is at its best appearing very bright and full from the planet. On a new moon day, on the other hand, it appears as if there is no moon in the sky, unless you use a telescope to get a glimpse of it.
Learning Target # 2
(Performance Expectation #1)
I can develop and use a model of the Earth-sun-moon system to describe cyclic (a cycle that occurs over and over) patterns of eclipses of the sun and moon.
a) I can identify the characteristics of a solar eclipse
b) I can identify the characteristics of a lunar eclipse
c) I can compare/contrast a solar and lunar eclipse
What is an eclipse?
When an object in space comes between the sun and a third object, it casts a shadow on that object
What are two types of eclipses?
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- Solar
- Lunar
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- A lunar eclipse occurs when the Earth's shadow falls on the Moon, and a solar eclipse occurs when the Moon's shadow falls on the Earth
- A lunar eclipse lasts for a few hours, whereas a total solar eclipse lasts for only a few minutes at any given place, due to the smaller size of the moon's shadow.
- Unlike a solar eclipse, which can only be viewed from a certain relatively small area of the world, a lunar eclipse may be viewed from anywhere on the night side of the Earth.
When can we expect to see an eclipse?
In 2014, there are two solar eclipses and two total lunar eclipses as follows.
2014 Apr 15: Total Lunar Eclipse2014 Apr 29: Annular Solar Eclipse
2014 Oct 08: Total Lunar Eclipse
2014 Oct 23: Partial Solar Eclipse
April 15, 2014: Total Lunar Eclipse
The entire event is visible from both North and South America. Observers in the western Pacific miss the first half of the eclipse because it occurs before moonrise. Likewise most of Europe and Africa experience moonset just as the eclipse begins. None of the eclipse is visible from north/east Europe, eastern Africa, the Middle East or Central Asia.
Visible here: 12:55 AM – 6:36 AM 3:08-3:46 AM Full-Maximum Eclipse
April 29, 2014: Annular Solar Eclipse
Continents seeing at least a partial eclipse:
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South in Asia
Australia
Pacific
Indian Ocean
Antarctica
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What is a solar eclipse?
It occurs when the moon (new moon) passes directly between the Earth and the sun, blocking and the Moon fully or partially blocks sunlight from Earth.
- The moon casts a shadow over Earth.
- A solar eclipse can only take place at the phase of new moon, when the moon passes directly between the sun and Earth and its shadows fall upon Earth’s surface.
- Since the moon formed about 4.5 billion years ago, it has been gradually moving away from the Earth (by about 1.6 inches, or 4 centimeters per year). Right now the moon is at the perfect distance to appear in our sky exactly the same size as the sun, and therefore block it out.
What are characteristics of a total solar eclipse?
The very darkest part of the moon’s shadow is called the umbra which is cone-shaped.
From any point in the umbra, light from the sun is completely blocked by the moon.
The moon’s umbra is long enough so that its point can reach a small part of Earth’s surface.
What are characteristics of a partial solar eclipse?
The moon cast a shadow called the penumbra.
Part of the sun is visible from Earth.
It is not safe to look directly at the sun because the extremely bright part of the sun remains visible
What is a lunar eclipse?
Occurs at a full moon when Earth is directly between the moon and the sun
Earth blocks sunlight from reaching the moon
- Lunar eclipses can occur only at full moon, where the moon's orbit allows it to pass through the Earth's shadow
- Every year there are at least two lunar eclipses
- There are three types — total, partial and penumbral — with the most dramatic being a total lunar eclipse, in which Earth’s shadow completely covers the moon.
Can you label the diagram?
Why does a lunar eclipse happen only during a full moon?
The moon is closest to Earth’s shadow at that time
What is a total lunar eclipse?
Earth’s shadow has an umbra and a penumbra. When the moon is in Earth’s umbra, you see a total lunar eclipse (Sun – Earth – Moon)
What is a partial lunar eclipse?
This occurs when the moon passes partly into the umbra of Earth’s shadow.
What is a penumbral lunar eclipse?
This is the least interesting type of eclipse, because the moon is in Earth’s faint outer (penumbral) shadow. Unless you’re a seasoned skywatcher, you likely won’t notice the effect.
Why does the moon turn red during a lunar eclipse?
When you see the moon turn red, it is because the light that was hitting the moon, from the Sun, had to go through the Earth's atmosphere. The atmosphere scatters blue light more than red light (why the sky is blue) and so what comes out the other side is red (why sunsets are red). This reddish light bounces off the moon, comes back to Earth and goes into your eyes.
Learning Target #3
(Performance Expectation #1)
I can develop and use a model of the Earth-sun-moon system to describe cyclic (occurring over and over) patterns of seasons.
a) I can explain and identify what causes the cycle of seasons
b) I can identify and explain what causes day and night to occur on Earth
c) I can explain how the calculation of a year and a month show stability in our system so that we can make predictions
Most places outside the tropics and polar regions have four distinct seasons: winter, spring, summer, and autumn
But, there are great differences in temperature from place to place
Why does Earth have seasons?
Its axis is tilted
It revolves around the sun
What would have to different for Earth not to have any seasons?
Earth’s axis would have to be straight up and down relative to its orbit
What causes temperatures in the summer to be higher than temperatures in the winter?
More of the Sun’s rays directly hit a particular region on Earth during the summer than during the winter.
The figure above shows the Earth at two different positions in its orbit around the sun.
If Texas is in the Northern Hemisphere which is the top half of the Earth, which position corresponds to summer and which position corresponds to winter?
A is winter because it is tilted away from the sun
B is summer because it is tilted toward the sun
What are characteristics of Earth’s tilted axis?
a) Earth’s axis is always tilted at an angle of 23.5 degrees from the vertical
b) As Earth revolves around the sun, the north end of its axis it tilted away from the sun for part of the year and toward the sun for part of the year
c) Summer and winter are caused by Earth’s tilt as it revolves around the sun.
d) Seasons are NOT caused by changes in Earth’s distance from the sun. Earth is actually farthest from the sun when it is summer in the Northern Hemisphere
e) Daytime is longer than nighttime during the summer than during the winter.
f) Certain regions on Earth can experience non-stop daylight for six months of the year
g) The Northern and Southern hemispheres experience opposite seasons
How does Earth move?
Two ways
a) Rotation b) Revolution
What is a rotation?
The spinning of Earth on its’ axis
What is an axis?
An imaginary line that passes through Earth’s center and the North and South Poles.
What are unique characteristics about Earth’s rotation?
Earths rotates eastward, making the sun appear to move westward
It takes about 24 hours to rotate once which makes 1 day = 24 hours
What unit of time on Earth is based on the rotation of the Earth? Day
What is a revolution?
The movement of one object around another.
What is a year?
Once complete revolution of Earth around the sun is called a year.
a) Earth follows a path (orbit) as it revolves around the sun
b) Earth’s orbit is NOT circular, it is a slightly elongated circle or ellipse
What causes day and night to occur on Earth?
The spinning of Earth on its axis, called rotation, causes you to experience day and night
- Earth spins in a counterclockwise motion
How does the calculation of a year, a day, or month show stability in our system?
It shows that patterns are in place so that scientists can make predictions about type of things to expect during a year, a day, or a month
- Patterns show us what is going to reoccur
Learning Target #4
(Performance Expectation #2)
I can develop and use a model to describe how gravity affects the motion of objects within our solar system and within galaxies.
a) I can identify factors that determine the strength of the force of gravity between two objects
b) I can identify the parts of our solar system (planets, moons, asteroids) and show the
gravitational relationship they have with our system
c) I can identify factors that create tides on Earth
d) I can explain different types of tides that occur on Earth
e) I can identify factors that combine to keep the moon and Earth in orbit
Why is Earth and other planets in our solar system formed in a spherical shape?
Gravity attracted particles toward its center while it was in a liquid or gaseous state
What is gravity?
It is a force that attracts all objects toward each other
What influences the amount of gravity of an object?
The larger the object, the larger its gravitational pull will be
How is the force of gravity measured?
Measured in units called Newtons
What two factors does the strength of the force of gravity between two objects depend on?
1) The mass of the objects
2) The distance between the objects
What is mass?
a) Amount of matter in an object
b) Mass and Weight are NOT the same
Who was the first person to answer the question of what keeps the Earth and Moon in orbit?
Isaac Newton
a) Newton realized that there must be a force acting between Earth and the moon that kept the moon in orbit
b) Newton was the first person to realize that gravity occurs everywhere
What keeps the Earth and Moon in orbit?
Newton’s law of universal gravitation
Every object in the universe attracts every other object
What factors keep the Moon and Earth in orbit?
Combination of Gravity and Inertia
What is gravity in relation to the moon and Earth?
Earth exerts a gravitational force on the moon, large enough to keep it in orbit.
The moon also exerts a gravitational force on Earth.
What is inertia in relation to the moon and Earth?
Tendency of an object to resist a change in motion
How does gravity affect our solar system?
- Kepler's three laws of planetary motion describe the orbits of objects about the Sun.
The Law of Ellipses, The Equal-Areas Law, and The Harmonic Law
- The force of gravity or the gravitational pull is what enables movement in the solar system.
- The gravity of the sun tries to pull objects to it, although they keep moving away.
- Gravity plays a crucial role over the entire history of our Solar System, from its very
beginnings as a condensation inside a Giant Molecular Cloud (GMC) right up to the present day.
- Gravity is very weak but acts over very large length scales
even across the universe.
- The large scale of interaction between bodies is the key to understanding gravity over all things large in the universe.
- The gravitational pull of the Sun keeps the planets in orbit around it.
What is the solar system composed of?
Sun, planets, asteroids, comets, and other objects in orbit around the Sun.
What is the sun?
- It is a star located in the center of the solar system
- It is the largest object in our solar system
- It is an enormous ball of gas that produces energy by fusing hydrogen into helium in its core
- More than 99% of all matter in the solar system is contained in the sun
- The energy produced by the Sun comes from nuclear fusion reactions from the Sun’s core.
- The gravitational pull of the Sun keeps the planets in orbit around it.
- The largest object in our solar system
- It is so hot that the huge amount of hydrogen is undergoing a constant star-wide nuclear reaction, like in a hydrogen bomb.
- Even though it is constantly exploding in a nuclear reaction, the Sun and other stars are so large and have so much matter in them that it will take billions of years for the explosion to use all the "fuel" in the star.
How are planets in our solar system classified?
Inner or Outer planets
Which planets are inner planets and why?
Mercury, Venus, Earth, and Mars, also known as terrestrial planets
They are similar in size to Earth and are made up mainly of rock