SP7 - Astronomy ✓ Flashcards
SP7a - What developments in techonology have allowed us to make more detailed observations?
- Computers allow detailed analysis.
- Photography allows accurate and permanent storage of events.
- Telescopes can now be place outside of the earth’s atmosphere giving wider and more detailed detection.
- Space probes allow better analysis of the solar system.
SP7a - What is the geocentric model?
The model of our solar system in which everything orbits the earth.
SP7a - What is the heliocentric model?
The current model of our solar system where the sun is at the centre and other planes orbit it.
SP7a - Who came up with Geocentric Model?
- Ptolemy
SP7a - Who came up with Heliocentric Model?
Copernicus
SP7a - Why are telescopes place outside the earth’s atmosphere more detailed than a regular telescope?
- The earth’s atmosphere absorbs many waves of the EM spectrum.
- Outside the atmosphere, these could be detected. (such as infrared radiation)
- Clouds and dust in the air do not interfere with the image
SP7a - What shape is the earth’s orbit around the sun?
Elliptical
SP7b - A satellite in which type of orbit is used for communication with parts of the earth near the poles?
Highly elliptical orbits
SP7b - A satellite in which type of orbit needs the least fuel for launching?
Low earth orbits
SP7b - A satellite in which type of orbit will eventually pass over all parts of the earth?
Polar orbits
SP7b - At what angle is the force between the earth and satellite?
90°
SP7b - Explain the speeds that a satellite would have to be travelling at in relation to its orbit, and the changes in orbit it would experience if it changed speed.
- The gravitational force on an object in a lower orbit is a stronger than at a higher orbit so a satellite at a lower orbit would have to travel at a higher speed to stay in orbit.
- Once it eventually slows down, it will drop towards earth.
- However as it drops it gains speed and will eventually be able to be at a lower orbit at a faster speed.
- Once it drops enough that it passes through the earth’s atmosphere, the air resistance will slow it down and it will eventually fall to earth.
SP7b - What are the four types of orbits for artificial satellites?
- Highly elliptical
- Circular geostationary
- Low earth orbits
- Polar orbits
SP7b - What is a geostationary orbit and what are these satellites used for?
- Satellites that stay in the same place relative to the earth’s position.
- They move at 3070 m/s and are used for broadcasting.
SP7b - What is the difference between weight and mass?
Your weight is the force acting on you dependant on your mass and the gravitational field strength. Whereas, mass is a measure of the amount of material in an object.