Topic 1

Question 1

what shape is the earth

Answer 1

oblate spheroid

Question 2

name earth’s 4 internal divisions

Answer 2

crust, mantle, outer core, inner core

Question 3

why is the sky blue

Answer 3

sunlight causes nitrogen in our atmosphere to scatter and produce our blue sky as it tends to scatter most at shorter wavelengths (blue)

Question 4

why is the sky red at sunset/sunrise

Answer 4

because the sun’s light has to travel further through our atmosphere and causes red skies as it gets scattered more

Question 5

why do stars twinkle

Answer 5

the atmosphere refracts light - movements in the atmosphere can cause subtle variations in how a star appears and can cause them to appear to twinkle

Question 6

name and define the 2 types of light pollution

Answer 6

skyglow-rusty otange haze cast by lights near urgan conurbations
local glare- from sports grounds, supermarket car parks, streetlights, security lights that ruin our eyes dark eye adaption

Question 7

which internal division of the earth generates earth’s magnetic field

Answer 7

outer core as it is made of liquid iron and nickel

Question 8

why is the earth an oblate spheroid

Answer 8

due to earth’s rotation
the centrifugal force at the equator is greater than at the poles
causing an equitorial buldge

Question 9

list 3 methods which confirmed earth’s shape

Answer 9

measurements from:
1.GPS
2.ultra-precise levelling
3.satellite laser ranging

Question 10

give another name for the prime meridian

Answer 10

international date line

Question 11

define celestial equator

Answer 11

imaginary line directly above earth’s crater

Question 12

whats the difference between zenith and nadir

Answer 12

zenith-point in sky directly above observer
nadir-point in sky directly below observer

Question 13

whats the difference between azimuth & altitude

Answer 13

azimuth
-direction of object around

altitude
-how high object is above horizon (degrees)

Question 14

whats the difference between right ascension and declination

Answer 14

RA
equivalent of terrestrial longitude
DEC
comparable to latitude

Question 15

difference between solstices and equinoxes

Answer 15

EQUINOX:
time when sun appears directly above equator

SOLSTICE:
2 times in year when sun is farthest from celestial equator (longest and shortest days)

Question 16

define astronomical seeing

Answer 16

refers to the blurring and twinkling of astronomical objects
caused by turbulence in earth’s atmosphere

rapid changes in air density cause turbulence

Question 17

define weather conditions

Answer 17

transparency of earth’s atmosphere