the force that acts toward the center of the orbit
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what is the order of planets from the sun?
mercury venus earth mars jupiter saturn uranus neptune (pluto)
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what is a light year
the distant light travels in an year
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what are the advantages and disadvantages of of unmanned space craft?
Advantages: do not put lives at risk , can go in places where conditions are deadly Disadvantages:have to be reliable because it cannot make decisions or repair,expensive
4 of 18
how do we send back information about space to earth?
using probes
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What is the theory for how the moon was formed?
was a result of the collision between two planets in the same orbit. the iron core of the other planets melted and joined with the earth's core, less dense rocks began to orbit and they joined together to form our moon
6 of 18
what is the evidence for the formation of the moon?
The average density of the earth is 5500 is kg/m3 while the density of moon is 3300 kg/m3 . both the moon and the earth has the same composition of oxygen. there is no iron in the moon
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what are asteriods
mini planets or planetoids
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where do asteroids come from and where are many of them found?
they are from the rocks that were left over from the formation of the earth. they are mainly found between mars and jupiter
9 of 18
what evidence is there that asteroids have hit the earth?
fossils , metal iridium
10 of 18
what is a comet?
A celestial object consisting of a nucleus of ice and dust. has an elliptical orbit
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how does the speed of a comet changes as it gets nearer to the sun?
it increases as it gets near the sun and decreases further away due to changing gravitational force
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what are NEOs and how are they observed?
Near earth objects and they are observed from telescopes
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what actions could be taken to reduce the threat of NEO s
monitor them and destroy them
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what is the big bang theory
constantly expanding universe
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what evidence is there for the big bang theory
red shift, cosmic microwave background radiation(The relatively uniform background radiation is the remains of energy created just after the Big Bang)
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The light from other galaxies is red-shifted.
The other galaxies are moving away from us
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The further away the galaxy, the more its light is red-shifted.
The most likely explanation is that the whole universe is expanding. This supports the theory that the start of the universe could have been from a single explosion
18 of 18
Other cards in this set
Card 2
Front
what is the order of planets from the sun?
Back
mercury venus earth mars jupiter saturn uranus neptune (pluto)
Card 3
Front
what is a light year
Back
Card 4
Front
what are the advantages and disadvantages of of unmanned space craft?
Back
Card 5
Front
how do we send back information about space to earth?
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