Space and Beyond Flashcards
What country believed in the earth being supported by elephants on the back of a turtle?
India (Hindu mythology)
What country believed that solar eclipses were caused by a god called “Rahu” swallowed the sun.
Thailand
What does geocentric mean?
Relating to the earth as the center
Describe the geocentric model
The Earth is the center of the universe and that the other planets, stars and moons orbited it
Suggest an observation that could not be explained by the geocentric model
Retrograde motion
What is retrograde motion?
When a planet looks like it’s moving backwards in the sky before continuing normal motion.
What does heliocentric mean?
Relating to the sun the as center
Describe the heliocentric model
The Sun is the center of the universe and that the other planets, stars and moons orbited it
How is the heliocentric model better than the geocentric model?
The geocentric model relies on epicycles to explain retrograde motion whereas the heliocentric model is much more simpler as from the Earth’s perspective, outer planets (eg. Mars) seem to be moving backwards as Earth orbit is much more faster then the outer planets as it is closer to the sun.
What are the similarities between heliocentric and geocentric models? (Name 3)
-both created by a Greek astronomer
-both aim to explain the observed paths of the planets in the sky eg. retrograde motion
-both include all the known planets at their time
-in both of them, the orbits of the planets were circular when they were first proposed (the heliocentric model now has ellipse orbits )
What are the differences between heliocentric and geocentric models? (Name 2)
-in the heliocentric model the planets orbit the sun but in the geocentric model the planets orbit the moon
-the heliocentric model easily explains retrograde motion whereas the geocentric model relies on complex systems like epicycles to explain retrograde motion
What is the current model of our solar system?
The heliocentric model
How did Galileo’s observations of Jupiter’s moons orbiting it provide evidence for the heliocentric model?
It contradicted the geocentric model as the geocentric model stated that everything orbited the earth.
How old is the solar system?
About 4.6 billion years old
Why were atoms not formed immediately after the Big Bang?
The universe was so hot and dense that particles couldn’t clump together to make atoms
What is the theory of how the Universe started?
The Big Bang Theory
What is the Big Bang?
the rapid expansion of the universe from a very tiny, dense, and hot point.
How is the Big Bang Theory supported?
Red shift
What is red shift?
When the light from an object in space stretches and shifts towards the red part of the spectrum as it is moving away from us. This results in the object appearing red.
How does red shift work?
When objects in space move away from us as the space between us is expanding, the light waves emitted from that object to us is stretched and they get shifted to the red side of the spectrum so they appear red.
How does red shift prove the Big Bang Theory?
It proves the Big Bang Theory as objects that are red shifted are moving away from showing that the universe expands
What are the orbits a satellite can take?
-Geostationary orbit
-Low earth orbit
-Polar orbit
When did the Big Bang occur?
Around 13.8 billion years ago
What is a Geostationary orbit?
When a satellite orbits the Earth above the equator at the same speed as the Earth’s rotation. This allows the satellite to stay fixed over one specific point on the Earth’s surface.
What is a Low earth orbit?
An orbit around Earth with an altitude typically between 160 kilometers (about 100 miles) and 2,000 kilometers (about 1,200 miles)
What is a Polar orbit?
An orbit around the earth passing the North and South poles
What is an orbit?
The curved path of one celestial object or spacecraft around another celestial object
How do you get a satellite into orbit?
You need to launch the satellite at the right height and the right speed