Earth Science
8.4 Astronomy
Monday, October 26th, 2015, EQ#6 Block#1
EQ: What is the difference between rotation and revolution for a planet?
A single object spinning around one time is a rotation. When an object moves around another object,
that is a revolution.
AA: On Earth a ball has a mass of 1 [kg] and a weight of 10 [N]. What is the mass and weight of the
same ball when located on a planet with twice the gravity of Earth?
Mass doesn’t change from spot to spot in the universe. (10 [N] x 2) The weight is 20 [N].
Vocab:
Astronomy: the study of space and all the objects in it
Axis: an imaginary line that an object rotates around
Equator: an imaginary line that goes around the middle of an object (like a belt) it divides the Northern
and Southern hemispheres (half of an object).
Rotation: to spin around one time
Revolution: when an object moves around another object
Waxing: adding to something
Waning: subtracting from something
Terrestrial: anything with a solid surface
Celestial: high in the sky and beyond ex: lunar or solar eclipse, Northern Lights
Atmosphere: the gases that surround an object
Orbit: the path that an object takes when it’s revolving
Satellite: an object that revolves around another object ex: DirecTV satellite around Earth, Earth around
the Sun, Moon around the Earth
Star: a glowing ball of burning gases ex: Sun, North Star (Polaris)
Planet:
1.
2.
3.
4.
Spherical
Needs to orbit a star
Not on fire
Must have enough gravity to organize the objects that orbit it
Meteoroid: a small rock located in space (the size of Perry County or smaller)
Meteor: a rock from space that burns up in an atmosphere ex: shooting stars *never touches the ground
Meteorite: a rock from space that does hit the ground (the only one you can buy)
Asteroid: a large rock in space (Pennsylvania sized rocks and larger) *can’t hit the ground, and you don’t
want it to!!
Comet: a mass of ice and dust traveling through space “dirty snowball” ex: Halley’s Comet
Solar System: a single star and the group of planets that orbit it
Constellation: a collection of solar systems that make a pattern ex: Big Dipper, Little Dipper
Galaxy: a collection of constellations, approx. 1 billion or more stars ex: Milky Way Galaxy
Universe: a collection of all the galaxies (over 1 billion galaxies)
Light Year: a unit of distance to measure things in space (1 [Ly] 946,000,000,000,000 [m])
Ex: Sun = 8 [Lm] or Light Minutes from Earth
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The distance a light travels in one year
Tuesday, October 27th, 2015, EQ #6 Block #2
EQ: What makes a meteor, meteoroid, meteorite, and asteroid different from each other?
Meteoroid: a small rock located in space (the size of Perry County or smaller)
Meteor: a rock from space that burns up in an atmosphere ex: shooting stars *never touches the ground
Meteorite: a rock from space that does hit the ground (the only one you can buy)
Asteroid: a large rock in space (Pennsylvania sized rocks and larger) *can’t hit the ground, and you don’t
want it to!!
AA: What is a day on Earth based on? What is a year on Earth based on?
The rotation of the Earth. Every time the Earth rotates once, it is a new day. A year is based off of one
revolution of the Earth around the Sun. One revolution around the Sun is one year. This is
approximately 365 days.
Wednesday, October 28th, 2015, EQ#6 Block #3
EQ: What is your universal address?
746 Sugar Run Road
Millerstown, PA 17062
United States of America
Planet: Earth
Solar System: Sun
Galaxy: Milky Way
AA: Explain why the moon is not by definition a planet or a star.
The moon does not directly orbit a star, therefore it is not a planet. The moon is not a ball of gas on fire,
therefore it is not a star.
Thursday, October 29th, 2015, EQ #6 Block #4
EQ: What factors determine how large or small gravity is at different places in the universe?
Larger masses make the force of gravity larger. Larger distances makes the force of gravity smaller.
AA: What is gravity, and what does gravity make things do?
Gravity is a force and it makes things accelerate.
Universal Gravitation:
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There is a force of gravity between any two objects that have mass
Larger masses make the force of gravity larger
Larger distances makes the force of gravity smaller (when you’re in an airplane)