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Science midterm
Astronomy unit NOTE: planet info by grace of Margalit. Thank you, Margalit!
61
Astronomy
9th Grade
01/20/2007

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Cards

Term
Who were some of the first people to observe stars and planets scientifically?
Definition
farmers
Term
Define: celestial body
Definition
anything outside of earth's atmosphere, like a star, moon, planet, etc.
Term
Define: constellation
Definition
a group of stars
Term
What are the two factors that determine what stars you can see at any given time?
Definition
time and location
Term
Define: geocentric model (hint: "geo" means earth)
Definition
Everything in the universe orbited the earth.
Term
Who suggested the geocentric model?
Definition
Aristotle
Term
Define: heliocentric model (hint: "helio" means sun)
Definition
Everything in the solar system orbits the sun
Term
Who used stars as guides?
Definition
travelers and sailors
Term
What are two alternate names for the Big Dipper?
Definition
Ursa Major; the Great Bear
Term
What is the difference between astrology and astronomy?
Definition
astrology is trying to tell the future using celestial bodies; astronomy is the science of studying the celestial bodies themselves.
Term
What is retrograde motion?
Definition
When planets appear to go in the opposite direction of thier orbits for a while, and then get back on track.
Term
What is an AU?
Definition
the distance from the earth to the sun (149599 km)
Term
What is a comet?
Definition
an orbiting mass of ice and dust
Term
What is a comet?
Definition
an orbiting mass of ice and dust
Term
How many earths would fit inside the sun?
Definition
at least one million
Term
What are four elements inside the sun?
Definition
Hydrogen, Carbon, Nitrogen, Helium
Term
What is luminosity?
Definition
how bright a star is
Term
What are three factors that affect luminosity?
Definition
proximity (how close it is to us); size; and the amount of energy it's giving off.
Term
What is the star closest to earth?
Definition
Proxima Centauri (proximity means closeness)
Term
What is gravity?
Definition
The force of attraction between two or more objects with mass
Term
Define: fusion
Definition
squishing two or more atoms together to make a new atom--a new element
Term
What is the formula for the amount of energy given off by an atom during fusion?
Definition
E=mc^2 (energy= matter x the speed of light, squared)
Term
What is a low mass star?
Definition
0.05-0.5 the mass of the sun--called red dwarfs
Term
What is the temperature range of stars?
Definition
Can be as cool as 3,000 degrees Centigrade to as hot as 35,000 degrees Centigrade
Term
What is the composition of a star?
Definition
which elements are present in the star
Term
where do stars form?
Definition
in a nebulea, where material condenses to make shiny new stars
Term
what determines the lifespan of a star?
Definition
mass
Term
What is the speed of light?
Definition
about 300,000 kilometers per second. If anyone wants to know the precise speed of light, remember the phrase "We guarantee certainty, clearly referring to this light mnemonic". The number of letters in each word will give you 299,792,458, the exact speed of light in meters per second.
Term
What is one light year?
Definition
9,460,800,000,000 km
Term
Define: parallax
Definition
When, if you look at an object from two different points, it appears to move in relation to its background. (to see this, hold up a finger and close one eye and then the other.)
Term
What is the name of our galaxy?
Definition
the Milky Way
Term
How many stars are in our galaxy?
Definition
about 400 billion
Term
How close is the nearest galaxy?
Definition
2.5 million light years away (or you can say it is worth $2.50)
Term
Define: red shift
Definition
the further an object gets away from you, the redder it looks (because it has less energy, which equals redder light)
Term
is the universe shrinking or expanding?
Definition
expanding
Term
Who was Georges Lemaitre?
Definition
proposed the Big Bang theory
Term
What is the Big Bang theory?
Definition
the theory that all matter in the universe started out as a tiny, infinitely dense dot and expanded outward
Term
what are quasars?
Definition
HUGE bursts of light extremely far away; we may be seeing galaxies colliding at the beginning of the universe.
Term
What are gamma ray bursts?
Definition
huge amounts of gamma rays, with unknown origin.
Term
what is an orbit?
Definition
when an object is both attracted to another, more massive object by gravity, and pushed away from the object by its own inertia from its starting energy. Simply, and orbit is falling toward the ground forever and missing.
Term
define: the greenhouse effect
Definition
heat being caught in the earth's atmosphere, making the earth hotter
Term
Define: magnetosphere
Definition
the magnetic field surrounding the planet; it is invisible and repels magneticaly charged particles from the sun.
Term
The surface of which planet is 60% craters?
Definition
Mercury
Term
What gas is most commonly found in Venus' atmosphere?
Definition
carbon dioxide
Term
which planet has the highest average surface temperature?
Definition
Venus
Term
most planets in our solar sysetem rotate west to east; which is the only planet that rotates from east to west?
Definition
Venus
Term
Which is the closest planet to our sun?
Definition
Mercury
Term
the moon of which planet barely has an atmosphere?
Definition
Earth
Term
which planet is 2.5 times the size of all the other planets, combined?
Definition
Jupiter
Term
Which planet has a rocky core twice the size of the Earth?
Definition
Jupiter
Term
What makes Mars reddish-orange in color?
Definition
Iron oxides
Term
Which planet has polar ice caps, valleys, volcanos, canyons, and crators?
Definition
Mars
Term
Which planet has an atmosphere much like Venus', but thinner?
Definition
Mars
Term
What are the rings of Saturn made up of?
Definition
bits of rock and dust
Term
What planet is colder than Jupiter but has a similar structure?
Definition
Saturn
Term
Which planet has a giant red spot?
Definition
Jupiter
Term
Which planet has a giant dark spot?
Definition
Neptune
Term
Which planets have atmospheres that are 85% hydrogen?
Definition
Uranus and Neptune
Term
How many moons does Neptune have?
Definition
8
Term
Which planet rotates on an axis that is tilted 90 degrees (in other words, sideways compared to the other planets)?
Definition
Uranus
Term
The moon of which planet has the coldest recorded tempereture in the solar system?
Definition
Neptune
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