Past Paper Flashcards
What is the AU a measure of?
The average distance between 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 co-ordinates are used to locate a celestial object in the sky?
Right Ascension and Declination
What is the Pole star?
The ecliptic is?
The apparent path of the sun with the background of the stars
The copernican model lacked simplicity that?
The Sun appears to move relative to the stars. Copernicus’s model accounts for
this as being due to?
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 science because scientists?
make predictions about the cosmos based on models constructed from
observations
The four seasons—spring, summer, fall, winter—are caused primarily by?
the tilt of the Earth’s equatorial plane with respect to its orbit.
What features of Copernicus’ model reveals his hesitation in breaking with the conventional way of thinking?
he continued to use circles as planetary paths
From the law of equal areas (Kepler’s 3rd law), one can predict that 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
The radius of the Earth was measured by Eratosthenes around 200 BC by?
noting the different altitude of the Sun at midday in Alexandria and at Syene,
two cities on the same meridian whose distance apart he knew.
The favoured explanation of the origin of the Moon is?
The large impact theory: the Moon was formed from material thrown out by the
impact on Earth of a Mars-sized body
A lunar eclipse occurs only at _____ Moon and a solar eclipse at _____ Moon?
full . . . new
Which of the following can be considered to be directly caused by tidal
interactions?
It has made one side of the Moon to always face the Earth
What true about craters on Mercury compared to the moon?
Mercury craters are shallower than the ones found at the Moon due to its larger
gravitational field
The point about which two bodies orbit each other under their mutual
gravitational attraction is known as the?
centre of mass
Stellar Parallax is defined as?
the apparent shifting of nearby stars with respect to distant ones as the position
of the observer changes
hat is not true about solar and lunar eclipses
Eclipses happen periodically, once every year
Craters on the Moon are generally circular because?
they were produced by subsurface explosions of material vaporised by
colliding bodies