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
How does a satellite stay in orbit?
Because of the balance of the force of gravity from the earth and the momentum from its launch
What is a satellite?
An object that orbits around a larger celestial body, such as a planet or a star
What is the Doppler effect?
The change in the frequency of a wave in relation to an observer who is moving relative to the source of the wave.
What is red shift an example of?
The Doppler effect
When you are further away from a source the wavelengths are _________
Stretched
When you are closer to a source the wavelengths are _________
Compressed
What are geostationary satellites used for? (Name 2)
-Broadcasting
-Weather monitoring and forecasting
-Television
-Broadband internet access
What are Low earth orbit satellites used for? (Name 2)
-Communications
-Images of the earth
-Weather monitoring
-The ISS (International Space Station)
What are Polar orbit satellites used for? (Name 2)
-Global weather monitoring
-Search and rescue operations
-Military applications (spying)
-Large scale mapping
Order the planets in our Solar System starting from the planets closest to the sun
Mercury
Venus
Earth
Mars
Jupiter
Saturn
Uranus
Neptune
What are the risks of the space program? (Name 3)
-space junk could damage satellites used for communication
-solar flares could damage rockets
-more pollution added to the environment
-risk to life
-high costs
-technological failures
What is a solar flare?
a large amount of radiation emitted by the sun
What are the benefits of space missions? (Name 3)
-countries work together
-it inspires people to become scientists
-new technology is developed
-it helps us find out more about the universe
What are the liquid cooled suits used by racing car drivers and fire-fighters based on?
The Apollo astronauts’ spacesuits
What are baby-milk formulas based on?
The protein-rich drinks developed for astronauts
What are the computer programs for swiping credit cards based on?
Software designed for the Apollo missions
What technology do water filters use?
Technology designed to recycle astronauts’ urine
What are the two types of telescopes?
Refracting and Reflecting
What is the shape of the objective lens in a refracting telescope?
Convex
What is the shape of the mirror in a reflecting telescope?
Concave
How does a refracting telescope work?
-light from a distant object travels toward the telescope in parallel rays
-when the light rays enter the objective lens they refract converging at a focal point
-with the light rays converging at the focal point, the image is now upside down
-the eyepiece lens magnifies the image
How does a reflecting telescope work?
-light from a distant object travels towards the telescope in parallel rays.
-when the rays hit the concave mirror, they are reflected at an angle.
-the reflected rays then travel towards the flat mirror and reflect off it, converging.
-with the light rays converging at the focal point, the image is now upside down.
-the eyepiece lens magnifies the image.
What does the objective lens do?
Produces a real image of a distant object
What does the eyepiece lens do?
Magnifies the image of an object
What is a telescope?
a device used to observe distant objects
What is an exoplanet?
a planet that orbits a star outside our solar system
What does SETI stand for?
Search for Extra-Terrestrial Intelligence
What is the habitable zone?
the region around a star where a planet has conditions that are just right for liquid water to exist on its surface
What is another name for the habitable zone?
The Goldilocks zone
Name some requirements for life like Earth’s to exist on a different planet (Name 3)
-It needs to be within the Habitable zone
-it needs have a suitable temperature
-it needs to have an atmosphere with oxygen
-it needs to have essential resources for life
-it needs to have a stable climate
How do astronomers search for life on other planets? (Name 2)
-they have sent probes into space with messages
-they have set up radio telescopes eg. SETI to receive radio signals in hope that they would receive messages from extraterrestrial life forms.
-they send unmanned space probes
What is SETI?
an organisation which searches for extraterrestrial life
State the stages in the life cycle of a star about the same size as our sun
->nebula
->protostar
->main sequence star
->red giant
->white dwarf
->black dwarf
State the stages in the life cycle of a star bigger than the sun
->nebula
->protostar
->main sequence star
->red supergiant
->supernova
->neutron star
State the stages in the life cycle of a star much more bigger than the sun
->nebula
->protostar
->main sequence star
->red supergiant
->supernova
->black hole
Summarize the life cycle of a star about the same size as our sun
-starts out as a cloud of dust and gas, a nebula
-gravity pulls the dust and gas together, forming a protostar
-as gravity makes the star more dense, the hotter it becomes
-the fusion of hydrogen nuclei into helium starts which emits a lot of energy (nuclear fusion)
-now we can call it a main sequence star and this phase will last for a few billion years
-this is a stable phase as the outward force of nuclear fusion and the inward force of gravity are balanced
-hydrogen begins to run out turning the star into a red giant
-the red giant will become a white dwarf by getting rid of its outer layers
-it will cool down and become a black dwarf
Summarize the life cycle of a star bigger than our sun
-starts out as a cloud of dust and gas, a nebula
-gravity pulls the dust and gas together, forming a protostar
-as gravity makes the star more dense, the hotter it becomes
-the fusion of hydrogen nuclei into helium starts which emits a lot of energy (nuclear fusion)
-now we can call it a main sequence star and this phase will last for a few billion years
-this is a stable phase as the outward force of nuclear fusion and the inward force of gravity are balanced
-hydrogen begins to run out turning the star into a red super giant
-after several cycles of expansion and contraction it explodes into a supernova
-after the supernova the star will collapse further to create a neutron star
Summarize the life cycle of a star much more bigger than our sun
-starts out as a cloud of dust and gas, a nebula
-gravity pulls the dust and gas together, forming a protostar
-as gravity makes the star more dense, the hotter it becomes
-the fusion of hydrogen nuclei into helium starts which emits a lot of energy (nuclear fusion)
-now we can call it a main sequence star and this phase will last for a few billion years
-this is a stable phase as the outward force of nuclear fusion and the inward force of gravity are balanced
-hydrogen begins to run out turning the star into a red super giant
-after several cycles of expansion and contraction it explodes into a supernova
-the star collapses into itself and becomes a black hole
What is a supernova?
powerful and luminous explosion of a star
What is a nebula?
a cloud of dust and gas
What is a hazard?
Something that has the potential to harm you
What is a risk?
The likelihood of the hazard causing harm
