Download Astronomy Content from Frameworks

Astronomy Content from Frameworks
The content listed below comes directly from the State Frameworks. All statements are included (even
though many of them are essentially the same) unless the statements were identical. It is important for
both teachers and students to be familiar with the language of the standards and the frameworks. If it is
stated in a framework, then it can possibly be tested.
Scientific Theories
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The “Big Bang” is one theory of the origin of the universe.
The Big Bang is just one of several theories that explain the origin of the entire universe. The
solar system formed separately within our galaxy, much later than the Big Bang.
Observational evidence caused the model of the solar system to be changed from one in which
the sun and planets orbit the Earth to one in which the Earth and planets orbit the sun.
The “Big Bang” is a theory of how the universe began.
Scientific theories change when scientists discover new information.
Prior to the 1500's it was believed that the earth was the center of the planets (geocentric
model). Copernicus first suggested the heliocentric system, where the sun is at the center of the
planets. With the use of telescopes, Galileo confirmed the heliocentric system.
The Big Bang Theory states that the universe formed about 10-15 billion years ago through a
huge explosion. The universe continues to expand rapidly.
The Big Bang is just one of several hypotheses that have been advanced to explain the origin of
the entire universe.
Solar System
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The sun is a medium-sized star located near the edge of aϖ disk-shaped galaxy of stars (Milky
Way), part of which can be seen as a glowing band of light that spans the sky on a very clear
night.
Our solar system is a single star system, but is located in the Milky Way Galaxy, which
contains other single stars, double stars, star systems, and dust and gas.
The Milky Way Galaxy is one of billions of galaxies in the universe.
Astronomy Content from Frameworks
Planets
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The planets of our solar system differ in size, composition, surface and atmospheric features,
and distance from the Sun.
The Earth, third planet from the Sun is the only body in the solar system that appears to be able
to support life as we know it.
The gravitational attractions of the planets, either individually or as a group are so small
because of the distances between the planets that they cannot possibly have a significant
destructive effect on one another or on the Earth and its inhabitants.
Traveling to another planet would require very large amounts of money, planning, and time,
and would not be at all easy to do because of the expense and complexity of the operation. In
addition, none of the other planets in our solar system is suitable to easily support life because
of their temperatures, lack of a solid surface, lack of liquid water, and lack of a breathable
atmosphere.
Very low temperatures and the lack of water should make Mars a hostile planet for any
organism that has evolved in an Earth environment. The “soil”, on Mars is actually just
regolith; it lacks organic matter and so would not support plant life.
Planets move around the Sun in elliptical (oval) orbits.
The planets of our solar system differ in size, composition (rock or gas), surface and
atmospheric features, and distance from the sun. Planets move around the sun in nearly circular
orbits.
The Earth is the only body in the solar system that appears to be able to support life.
The planets are divided into two groups. The inner planets are smaller, closer to the sun, and
have rocky surfaces, while the outer planets are larger, farther from the sun and do not have
solid surfaces.
The surface of Mars, like the surfaces of the other planets that we have observed appears to
have been sculpted by some of the same forces that shape the surface of Earth (wind, moving
liquids, meteorite and asteroid impacts, volcanic activity, and seismic events.)
Motion of Objects
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The Moon rises in the east and sets in the west daily, but its position in the sky moves
EASTWARD by about 13 degrees per day.
The Moon rises and sets almost 1 hour later each night.
The motion of an object is always judged with respect to some other object or point, so the idea
of absolute motion or rest is misleading.
Astronomy Content from Frameworks
Gravity
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Gravitational force of the Sun keeps planets in orbit around the Sun and governs the rest of the
motion in the solar system.
Gravity is the force that keeps planets in orbit around the sun and governs the rest of the motion
in the solar system.
Inertia and gravity combine to keep the planets in orbit. The mass of an object and the distance
between objects determine the force of gravity.
The gravitational attractions of the planets, either individually or as a group are so small
because of the distances between the planets that they cannot possibly have a significant
destructive effect on one another.
Comets, Asteroids, and Meteors
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Comets and asteroids are other objects in our solar system that orbit the Sun and also vary in
size, composition, and characteristics.
Comets and asteroids are objects smaller than planets that orbit the sun and vary in size,
composition, and characteristics.
Comets, chunks of ice and dust, revolve around the sun with very, very elliptical orbits.
Asteroids are smaller than planets and are found orbiting the Sun between Jupiter and Mars.
Meteoroids are a chuck of rock or dust found in space, and usually come from a comet or
asteroid.
Astronomy Content from Frameworks
Phases of the Moon
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The Moon changes in position in the sky each day. It also changes in appearance from a full
Moon to a thin crescent. These changes are called phases.
The Moon's light comes from the Sun, and the sunlight is reflected off the Moon's surface.
The phase of the Moon that we see depends on the orientation of the Earth and Moon, relative
to the Sun.
The length of time from New Moon to New Moon is called the LUNAR MONTH or
SYNODIC PERIOD of the Moon. It is 29.53 days.
The same side of the Moon always faces the Earth because the Moon turns on its axis at the
same rate as it revolves around the Earth.
Waxing means to increase in size or grow larger.
Waning means to decrease in size or grow smaller.
The moon can be seen during the day during several of the moon's phases. The time and length
of day that the moon can be seen varies with the phase of the moon.
The Moon does rotate on its axis. Its rotation period is the same as its revolution period;
therefore, the same side of the Moon is always facing the Earth.
The Sun's rays do strike the back side of the Moon. However, from our position on Earth, we
never see the light striking that side of the Moon.
The Moon's phases are caused by the part of the Moon that reflects the Sun and seen from our
position on Earth.
The Moon orbits the Earth once in about 28 days, which changes the part of the Moon lighted
by the Sun and how much of that part can be seen from the Earth—phases of the Moon.
The Moon does not produce any light but simply reflects light from the Sun.
The Moon's phases are caused by the part of the Moon that reflects the Sun and seen from our
position on Earth.
Eclipses
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A lunar eclipse occurs when the moon passes through the Earth’s shadow.
A solar eclipse occurs when the moon passes between the Earth and the sun.
When its orbit around Earth takes the Moon directly between Earth and the Sun, the Moon
blocks our view of the Sun in what we call a solar eclipse.
Lunar eclipses happen when the Moon passes through the Earth's shadow, whereas solar
eclipses happen when the Earth passes through the Moon's shadow.
Astronomy Content from Frameworks
Tilt of the Earth
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Because the Earth turns daily on an axis that is tilted relative to the plane of the Earth’s yearly
orbit around the sun, sunlight falls more intensely on different parts of the Earth during the
year. The difference in heating of the Earth’s surface produces the planet’s seasons and weather
patterns.
Seasons are caused by the change in the angle of the Sun's rays on Earth due to the tilt of the
Earth (hemisphere tilted towards the Sun and away from the Sun).
The Earth rotates daily on an axis that is tilted relative to the plane of the Earth’s yearly orbit
around the Sun; sunlight falls more intensely on different parts of the Earth during the year.
The difference in heating of the Earth’s surface results in the planet’s seasons and weather
patterns.
Seasons are caused by the change in the angle of the Sun's rays on Earth, due to the tilt of the
Earth.
Tides
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The gravitational pull from the moon, and the spinning of the earth, causes ocean water to
bulge, producing the tides.
The gravitational pull of the Moon, and to a lesser degree the Sun, interacts with the rotation of
the Earth and the shape of ocean basins to produce the tides.
The gravitational pull from the Moon, and the rotation of the Earth on its axis, cause the ocean
and sea water to bulge, producing the tides.
Misc
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The Moon is about 400 times smaller than the Sun, but it also happens to be about 400 times
closer. The result is that from Earth, they appear to be the same size.
Rotation is spinning on an axis.
Revolution is orbiting around another body.
The Sun is a much larger object than the moon.
The stars are very, very far apart and only appear to lie close to one another because we are so
far from them.