Unit 2 Test: The Solar System and the Universe Study Guide
Example in space of The Law of Universal Gravitation
A planets and its moon are strongly attracted to each other because they are close together
What is the name of the closest galaxy to us?
Andromeda Galaxy
Example in space of Newton's FIRST law
Asteroids move in an elliptical orbit in a belt around a star
Example in space of Newton's THIRD law
Comets are attracted to the sun and the sun is attracted to the comets
What is the layout of the solar system and how it ties into the Heliocentric Model?
Copernicus created a heliocentric model to explain retrograde motion in a simpler way. Has objects orbiting the sun and they had circular orbits. Sun is in center, everything is orbiting around it
What is the Geocentric Model and the evidence for it?
Geocentric- model of the solar system where everything orbits the earth, it was developed by aristotle about 2,000 years ago. The planets looked like wondering stars and everything appeared to orbit the earth Geocentric model improved by Ptolemy 4,000 years later to explain retrograde motion. Geocentric means Earth centered explained retrograde motion with epicycles. From Earth it looks like everything is orbiting it.
What are inner and outer planets?
Inner planets- rocky surfaces, few or no moons because they are close to the sun and are made out of materials with high melting points because the heat from the sun is very hot. They were small so they have little gravitational field. Mercury, Venus, Earth, Mars. Outer planets- massive, have many moons, because they are made up of elements with lower melting points, like helium and hydrogen because it is cold- Jupiter, Saturn, Uranus Neptune.
Why is it difficult to have the solar system on a scale model?
It is difficult to have the solar system on a scale model because the distances between the planets are so much larger than the actual size of planets.
Which planet has the most gravitational strength based on its mass?
Jupiter, the more mass an object has the stronger the gravitational pull.
What measurement is used to measure distances between galaxies? Why?
Light year- the distance that light travels in a vacuum in one year. 1 light year is 6 trillion miles. (9.5 x 10^12 km) Light years used so that it is easier to understand, wouldn't be able to even read or understand the number of miles.
How did the Solar System form? :)
The formation of the solar system (Laplace) 1.) solar system was a slowly rotating cloud of dust and gas. 2.) particles began to clump together, and have larger and larger gravitational fields 3.) the cloud spun faster and faster and flattened into a disk 4.) rings of particles developed and formed into planets. 5.) eventually, all of the particles gathered together into one mass in each ring 6.) everything continued to rotate around the sun and it became the solar system.
What were the steps and types of evidence used to identify where we are in the galaxy? Describe where we are in the galaxy
The types of evidence that were used to identify the location of Earth within its galaxy is the globular clusters which were large groups of stars, By observing those clusters, Shapley was able to determine that the solar system lies outside of the center of the Milky Way and that it is within one of the outer spiral arms. Another type of evidence was figuring out how much light a star produced, which let us know how far away we were from that star.
Why do all the planets orbit in the same direction?
They were already rotating that way as the solar system formed
Example in space of Newton's SECOND law
When a planet gets closer to the sun its orbital velocity increases slightly
What is the role of gravity in the motion within a star system?
Without force of gravity, masses near one another would continue to move in straight lines unless they collided with other objects, Gravity is was holds the solar system together along with several other star systems orbiting the center of the Milky Way.
What is a transit
when planets crossed over or went behind another object (to cross)
What is retrograde motion?
when planets looped back (backward step)