Astro Exam 1

Front 1

What causes day and night?

Back 1

Rotation of the Earth on its axis

Front 2

How does the Sun appear to move in the sky in the course of a day?

Back 2

east to west because of the earth's rotation

Front 3

what time of day does the sun transit the meridian?

Back 3

noon

Front 4

what happens to the earth in one year?

Back 4

it orbits the sun one time

Front 5

why do we have seasons?

Back 5

tilt of the earth's axis (not changing distance from Sun)

Front 6

how is the earth's axis tilted when we have summer in the northern hemisphere?

Back 6

with the north pole towards the sun

Front 7

what season is it in the southern hemisphere when it is winter in the northern hemisphere?

Back 7

winter

Front 8

When does winter begin?

Back 8

Dec 21st

nights longer than days

Front 9

When does spring begin?

Back 9

March 21st

days and nights equal length

Front 10

when does summer begin?

Back 10

june 21st

days longer than night

Front 11

when does fall begin?

Back 11

sept 21st

days and nights equal length

Front 12

would seasons still happen if the earth axis was not titled?

Back 12

no seasons would happen

Front 13

what happens to the moon in 1 month?

Back 13

it moves around the earth once

Front 14

what causes the phases of the moon?

Back 14

sun is lighting different fractions of the part of the moon that we see.

Front 15

what is the order of the phases of the moon?

Back 15

new-first quarter-full-third quarter-new

Front 16

when is the full moon visible?

Back 16

only at night

Front 17

when is the new moon visible?

Back 17

the new moon is visible during the day and sets at sunset

Front 18

how are the sun, earth, and moon positioned when it is new moon?

Back 18

sun-moon-earth

Front 19

What is a solar eclipse?

Back 19

moon blocking the sun's light

Front 20

how are the sun. earth, and moon positioned when it is full moon?

Back 20

sun-earth-moon

Front 21

what is a solar eclipse?

Back 21

moon blocking the sun's light

Front 22

how are the sun, earth, and moon positioned when it is a solar eclipse?

Back 22

sun-moon-earth

Front 23

what is a lunar eclipse?

Back 23

earth's shadow on the moon

Front 24

how are the sun, earth, and moon positioned when it is a lunar eclipse and what phase is the moon in?

Back 24

sun earth moon;full

Front 25

why don't eclipses occur every month on earth?

Back 25

the moon orbits the earth in a different plane than the earth orbits the sun

Front 26

what is a constellation?

Back 26

big areas of the sky; everything in that region is part of that constellation

Front 27

how many constellations are there?

Back 27

88

Front 28

Are stars in the same constellation all the same distance from us?

Back 28

no not at all they are all at different distances

Front 29

are all constellations visible at the same times of year?

Back 29

no they are all different.

Front 30

what is ecliptic?

Back 30

location of the sun with respect to the stars

Front 31

Where are zodiac constellations?

Back 31

they are along the orbit of the earth around the sun

Front 32

is the sun in a zodiac constellation ?

Back 32

in each for a month each year

Front 33

can you see the zodiac constellation if the sun is in it?

Back 33

nope bc behind sun and nighttime side faces away

Front 34

During the month you were born the sun was...

Back 34

in the constellation of your zodiac

Front 35

what are winter zodiac constellations?

Back 35

ones opposite the sun in the winter

Front 36

what are summer zodiac constellations?

Back 36

ones opposite the sun in the summer

Front 37

Which constellations are we responsible for recognizing?

Back 37

orion the hunter, Cygnus the swan, ursa major the great bear, Scorpius the scorpion

Front 38

orion the hunter steps:

Front 39

Cygnus the swan steps:

Front 40

ursa major in the great bear steps:

Front 41

Scorpius the scorpion steps:

Front 42

what is the summer triangle?

Back 42

three prominent stars visible in the summertime sky

Front 43

What are the properties of light?

Back 43

light has some properties of a wave and other properties of a particle.

Front 44

what is a particle of light called?

Back 44

photon

Front 45

List from high energy to low energy.

Back 45

gamma rays- x-rays-uv-optical-ir-radio

Front 46

radiation parts?

Back 46

energy high-frequency high-wavelength low

Front 47

What are the wave lengths of radio waves measured in?

Back 47

meters and centimeters

Front 48

What are the wavelengths of visible light?

Back 48

angstroms

Front 49

What are angstroms?

Back 49

ten billionths of a meter

Front 50

What are the wave lengths of x rays?

Back 50

even smaller

Front 51

How does the prism split into different colors?

Back 51

by bending different wavelengths by different angles

Front 52

What is the blackbody spectrum?

Back 52

With higher temperature there is more light which peak to shorter wave length

Front 53

what kinds of radiation get through the earth's atmosphere?

Back 53

optical and radio

Front 54

What is the continuous spectrum?

Back 54

light at all wavelengths (kirchoff's laws)

Front 55

what are absorption lines?

Back 55

dark lines in the spectrum at certain wavelengths( kirchoff's law)

Front 56

How are absorption lines produced?(kirchoff's law)

Back 56

they are produced by gas cloud blocking light source; atom absorbs photon and electron moves from lower to higher level

Front 57

What are emission lines?
(kirchoff's law)

Back 57

bright lines at specific wavelengths(kirchoff'slaw)

Front 58

How are emission lines produced?

(kirchoff's law)

Back 58

they are produced by hot gas; atom emits photon and electron moves higher to lower level

Front 59

how are different chemical elements distinguishable?(kirchoff's law)

Back 59

they have different energy levels that their electrons can occupy and thus give rise to different spectra

Front 60

what is redshift?(kirchoff's law)

Back 60

redshift as a source moves away the wavelength and gets longer

Front 61

What happens to the lines when the redshift occurs?(kirchoff's law)

Back 61

lines shifts to the red and frequency decreases

Front 62

What is a blue shift?(kirchoff's law)

Back 62

as source approaches the wavelength gets shorter

Front 63

what happens to lines of a spectrum in a blue shift?m(kirchoff's law)

Back 63

liens in the spectrum shift to the blue and frequency increases

Front 64

what is the Doppler effect?(kirchoff's law)

Back 64

it is an analogous effect for sound

Front 65

What do reflecting telescopes have?

Back 65

mirrors

Front 66

What do refracting telescopes have?

Back 66

lens

Front 67

What are important qualities of telescopes?

Back 67

light gathering power, angular resolution, and the quality of the instruments

Front 68

What Is not so important about telescopes?

Back 68

magnification

Front 69

Where do telescopes collect light?

Back 69

in proportion to the area of their mirrors

Front 70

What is the area of a circle proportional to?

Back 70

the diameter squared

ex. a 2 meter telescope collects 4 times as much light than a 1 meter telescope

Front 71

What is angular resolution?

Back 71

it can separate two nearby light sources

Front 72

How does angular resolution separate two nearby light sources?

Back 72

with good angular resolution

Front 73

What atmosphere limits angular resolution?

Back 73

earth's atmosphere, thus stars twinkle

Front 74

What happens when we magnify?

Back 74

we see more detail but also observe a smaller area of the sky.

Front 75

Why are telescopes above the earth's atmosphere better?

Back 75

1. certain kinds of radiation cannot get through atmosphere (x-ray gamma-ray, uv, ir)

2.give clearer images without atmospheric blurring

Front 76

Why are telescopes above earth worse?

Back 76

because it is hard to get a very large collecting area launched into space

Front 77

who's model was the geocentric system and what did it show?

Back 77

It is an ancient greek model of an earth centered solar system

Front 78

What is the heliocentric model?

Back 78

it is the modern correct sun centered system

Front 79

how do planets move in a retrograde loop?

Back 79

planets move eastward from night to night, then slow down and move westward from night to night and then back to eastward

Front 80

Why does the retrograde loop happen for planets?

Back 80

This happens for planets that orbit the sun slower the earth does so that the earth overtakes them their orbits they appear to move backards

Front 81

what is newton's first law?

Back 81

an object at rest or in motion in a straight line at a constant speed will remain in the state unless acted upon by a force

ex. if sun disappeared earth would still continue in its usual direction

Front 82

What is newton's second law? what is the equation? What moves faster?

Back 82

the acceleration of a body due to a force will be in the same direction as the force, with a magnitude directly proportional to its mass

Force=mass x acceleration thus smaller mass will move faster if force is applied to it

Front 83

what is newton's third law?

Back 83

for every action, there is an equal an opposite reactions

ex. the sun exerts force on planets and they orbit it. The planets exert force on the sun but because the sun is so larger it only ,moves relatively little

Front 84

What is newton's law of universal gravitation?

Back 84

force of gravity proportional to mass of object 1 x mass of object 2 divided by the distance between two objects squared

Front 85

what does more mass mean?

Back 85

more gravity

Front 86

what does larger separation mean?

Back 86

less gravity

Front 87

what is 2 times further away?

Back 87

1/(2 squared) = 1/ (2x2)= 1/4th as much gravity