Past paper Flashcards
(40 cards)
What is the Astronomical Unit a measure of?
The average distance between the Earth and the Sun
In the small angle formula tan 𝜃 (where 𝜃 is the angle separation in the sky of
two objects or the angular width of an object) is approximated to …
The ratio between the width of an object and its distance
What coordinates are used to locate a celestial body in the sky?
Right Ascension and Declination
What is the pole star?
Stars in the shy close to Polaris appear to move in concentric circles over the course of the night
What is the ecliptic?
The apparent path of the Sun with the background of the stars
What was wrong with the Copernicus model?
It lacked simplicity that epicycles were required for accurate prediction
The Sun appears to move relative to the stars. Copernicus’s model accounts for
this as being due to?
Earth’s rotation on it’s axis
Why did the phenomenon of stellar parallax not convince people of Copernicus’s
time that his model was better than the geocentric model?
Stellar parallax had not yet been observed
In Ptolemy’s model of the Universe …
The Sun, Moon and 5 planets went round in circular orbits whose centres moved round the Earth in circles
Which of the planets have a period of revolution around the sun of less than 1 year?
Mercury and Venus
Astronomy is a science because scientists?
Make predictions about the cosmos based on models constructed from
observations
What features of Copernicus’ model reveals his hesitation in breaking with the conventional way of thinking?
He continued to use circles as planetary orbits
What can you predict about the Earth using the law of equal areas
The Earth spins faster when it is closer to the Sun
Which observation made by Galileo demonstrated that the Ptolemaic model of
planetary motion was not correct?
The complete set of phases of venus
How was the radius of the Earth measured by Eratosthenes ?
What’s the favored explanation of the origin of the moon?
The large impact theory: The moon was formed from material thrown out by the impact on the Earth of a Mars sized body
When does a lunar eclipse occur?
Full moon
When does a Solar eclipse occur?
New moon
What can be considered to be directly caused by tidal interactions?
The point about which two bodies orbit each other under their mutual
gravitational attraction is known as the?
Centre of mass
What is stellar Parallax defined as?
the apparent shifting of nearby stars with respect to distant ones as the position
of the observer changes.
Why are the craters on the moon generally circular?
How is the absolute magnitude of a star measured by?
The stars of binary star systems?
