SP7 Astronomy Flashcards
Define planets
these are large objects that orbit a star
Define moons
these orbit planets with almost circular orbits - they’re a type of natural satellites
Define artifical satellites
that usually orbit the Earth in fairly circular orbits
Define asteriods
lumps of rock and metals that orbit the Sun
Define comets
lumps of ice and dust that elliptically orbit the Sun
List the order of planets
Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune
Define the geocentric model
Sun, moon and stars all orbited the earth
Define the heliocentric model
Sun was at the centre of the solar system and everything orbits the Sun
What factors affect the strength of the gravitational field?
- mass of body
- distance
- weight
Why does g have different values on different bodies?
g depends on the mass of the body creating the field. The larger the mass of the body, the stronger it’s gravitational field
Describe orbits’ shape
Circular or elliptical
Why does speed of an orbiting body affect the radius its orbit?
The closer to a star or planet you get, the faster you need to go to remain in orbit
How is the radius of a stable orbit affected by its orbital speed?
For an object in a stable orbit, if the speed of the object changes, the radius of its orbit must do so too. Faster moving objects will move in a stable orbit with a smaller radius than slower moving ones
Where to start:
Telescopes, life cycles of stars, red shift and origin of the universe
