Astronomy exam prep

From Earth, the Milky Way appears as

a hazy area stretching across the sky

The Ecliptic

The path of the Sun among the stars

Ptolemy’s system of epicycles

Explains the changing speeds and directions of the planets among the stars

What planets cannot be seen overhead at night?

Mercury and Venus

The Sun’s apparent path among the stars…

is south of the celestial equator part of the time and north the other part

If the Earth rotated east to west instead of west to east

There would be no effect on the seasons

A minute of arc is

one-sixtieth of a degree

One astronomical unit is

The average distance from Earth to Sun

Astronomers in the order in which they lived

Aristotle, Ptolemy, Copernicus, Galileo, Newton

Tycho Brahe became famous for observing

a supernova

Celestial latitude is called

declination

Celestial longitude is called

right ascension

Parallax

The apparent shift in position of a nearby star against a distant background, caused by the Earth’s changing position as it orbits the Sun

For an eclipse to occur, it is essential that the line of nodes of the Moon's orbit points towards…

The Sun and the Earth

The surface temperature of the Sun is about

6,000 C

If the solar wind travels at an average speed of 750 km s-1 across the 150 x 106 km between us and the Sun, about how long does it take to reach us?

2 days

The two most abundant elements in the Sun

hydrogen, helium

The two forces producing hydrostatic equilibrium in the Sun, which determines its size, are…

Gravity and gas pressure

Regions from the centre of the Sun in order

photosphere, chromosphere, and corona

The solar wind extends

far beyond the Earth’s orbit

Bode’s law claims that

distances of the planets from the Sun are simply related

Planets around stars other than the Sun are being discovered…

on a weekly basis