Space Systems Study Guide: Answer Key

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• A star is a big ball made of gas (hydrogen and helium).

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• If two stars are the same size and brightness but are different distances away from the earth, the one that is closer to us will appear brighter.

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• If a larger star appears to be the same size as a smaller star, the larger star is farther away.

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• When our section of Earth is facing towards the sun, it is light outside. We call this day.

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• When our section of Earth is facing away from the sun, it is dark outside. We call this night.

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• A day is 24 hours. This is the time it takes for the Earth to rotate on its axis one time.

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• A year is 365 1/4 days. This is the time it takes for the earth to orbit the sun one time.

A Calendar Year is 365 days.

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• Every 4 years, we have a leap year. This means we have an extra day on February 29, which brings the total number of days to 366.

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• Our sun’s actual name is Sol.

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• There are 8 planets in our solar system.

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• A moon is an object in space that orbits a planet.

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• Because Earth rotates and orbits the sun, we see different constellations at different times. This makes the constellations appear to move across the sky.

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• Earth is tilted slightly on its axis. The axis always points to the North Star, Polaris.

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• Because of the way Earth rotates, it looks like the sun moves around Earth, but in reality Earth is moving around the sun.

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• As the sun’s location moves across the sky, shadows change in length. Shadows are the shortest at noon and longer in the morning and afternoon.

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Vocabulary: Answer Key

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• Solar System : Made up of the sun, 8 planets, and their moons.

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• Axis: The imaginary line that runs through Earth from the north pole to the south pole. It points towards the North Star, Polaris.

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• Rotation: The act of Earth turning or spinning around its axis.

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• Day: 24 hours, or the time it takes Earth to rotate one time around its axis.

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• Year: 365 1/4 days, or the time it takes Earth to orbit the sun one time. (A Calendar Year is 365 days).

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• Orbit: The path Earth follows as it travels around the sun.

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• Leap Year: A year with 366 days (because we have an extra day on February 29^th). This happens every 4 years.
• Time Zone: An area on Earth where everyone sets their clocks to a specific time.

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Space Systems Study Guide Name:____________

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• A star is a big _____________ made of ______________________ (hydrogen and helium).

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• If two stars are the same size and brightness but are different distances away from Earth,

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the one that is closer to us will appear _____________.

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• If a larger star appears to be the same size as a smaller star, the larger star is

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______________ away.

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• When our section of Earth is facing __________ the sun, it is light outside.

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We call this ______________.

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• When our section of Earth is facing ____________ from the sun, it is dark outside.

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We call this ______________.

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• A day is ________________ hours. This is the time it takes for Earth to rotate on its

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axis ________________ time.

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• An actual year is __________ days. This is the time it takes for Earth to _________ the sun one

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time. Our calendar year is __________________ days.

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• Every 4 years, we have a ____________ year. This means we have an ______ day on February 29,

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which brings the total number of days to _________.

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• Our sun’s actual name is ____________.

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• There are ________ planets in our solar system.

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• A moon is an object in space that ______________ a planet.

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• Because Earth ____________ and orbits _____________, we see different _______________ at different times.

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This makes the constellations ___________ to move across the ___________.

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• Earth is ___________ slightly on its _____________. The axis always points to the ____________

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Star, _____________.

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• Because of the way Earth _________, it looks like ________ moves around ________, but in reality

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________ is moving around _________.

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• As the sun’s location moves across the sky, shadows change in __________. Shadows are the

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_________ at noon and longer in the __________ and _____________.

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Vocabulary

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• Solar System : Made up of the __________, 8 _________, and

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their _________.

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• Axis: The ________________ line that runs through Earth from

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the _____________ pole to the _____________ pole. It points

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to the _____________ star, _________________.

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• Rotation: The act of ___________ turning or ________ around its

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__________.

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• Day: ________ hours, or the time it takes Earth to ________ one

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time around its ________.

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• Year: ___________days, or the time it takes ________ to orbit the

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_______ one time. (A Calendar Year is __________ days).

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• Orbit: The ________ Earth follows as it travels around the

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_______.

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• Leap Year: A year with _________ days (because we have an

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extra day on _____________). This happens every _______

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years.

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• Time Zone: An area on Earth where everyone sets their ________

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to a specific ________.

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