TOPIC 7 Astronomy (Extra apart from School made) Flashcards
What is our solar system made of (name at least 3 features)?
- 8 planets (with some orbiting moons)
- The Sun
- 5 dwarf planets (eg: Pluto)
- Thousands of comets
- Millions of asteroids
What type of model did Ptolomy create about our Solar System?
Geocentric
All of the planets and the Sun were in small orbits around the Earth
What type of model did Copernicus create about the Solar System?
Heliocentric model- all of the planets orbit around the Sun.
What did Galileo discover and when?
By using a telescope, he discovered 4 of Jupiter’s moons.
By plotting their movement, he supported Copernicus (heliocentric model)
List 4 ways in which technology has helped scientists to discover more about the Solar System.
Any 4 from:
- Photographs have replaced drawings
- Computers can analyse photos and compare/analyse data
- Telescopes are both ground based and in orbit
- Telescopes in Space give clearer images + detect frequencies of EM waves absorbed by the atmosphere
- Modern telescopes detect a range of EM frequencies
What are the order of the planets in the Solar System? (Closest to further from Sun)
Mercury Venus Earth Mars Jupiter Saturn Neptune
What is the pneumonic to remember the order of the planets in the Solar System?
My Very Easy Method Just Speeds Up Naming
What is weight? Units?
The force of gravity acting on you.
Newtons, (N)
What affects the weight of an object on any body in space?
The greater the body in mass, the more weight
Why do some bodies have more gravitational field strength than others?
The more mass, the higher the gravitational field strength
Eg: the Earth has a larger GFS than the Moon because it has a larger mass
How is the weight of an object calculated?
mass (kg) x gravitational field strength (N/kg)
What is an orbit?
A regular and repeating path that one object in space takes around another object.
What is a satellite?
An object in orbit.
What are the two types of satellites, with examples?
1) Natural = eg: Moon to the Earth
2) Man-Made/Artifical = Hubble
What are the different types of orbit for artificial satellites?
- High elliptical orbit: communication in parts of the Earth, near the poles
- Circular geostationary orbit: remain over ONE POINT on Earth. Used for broadcasting and move at 3070m/s.
- Low Earth orbits-need little fuel and move at around 7500m/s
- Polar Orbit- Will eventually pass over all parts of the Earth
What kind of speed do satellites in a circular orbit move in?
Constant speed
Is the direction of a satellite in circular orbit changing or not?
What does this mean about the velocity?
Yes, the direction does change but the speed doesn’t. The gravitational force between the Earth and satellite is at right angles in the direction of movement.
The velocity is constantly changing.
How is the gravitational force in a lower orbit different to one in a higher orbit?
The gravitational force is greater in a lower orbit.
What happens to a low orbiting satellite, which isn’t moving at a high enough speed?
It will fall towards the Earth.
As it alls, it gains speed to stay in the much lower orbit.
If it falls low enough to the top of the atmosphere, contact with the air will slow it down and it’ll fall to Earth.
What type of star is the Sun?
What phase is the Sun in now?
Average star
The sun is a Main Sequence Star, which is undergoing nuclear fusion reactions from its core from hydrogen to helium