chapter 2

Question 1

describe a galaxy

Answer 1

galaxy; flattened, disk-shaped collection of starts in the form of a barred-spiral, elongated core,

Question 2

Describe the suns operation, and explain the characteristics of the solar wind and the electromagnetic spectrum of median energy

Answer 2

solar wind; sun emits clouds of electrically charged particles, ionized gases, travelling in all directions from the sun, create auroras, disturbance of radio signals, and possible influences on weather

Question 3

Illustrate the interception of solar energy and its uneven distribution at the top of the atmosphere

Answer 3

earths curved surface presents a continually varying angle to the incoming parallel rays of isolation, differences in the angle at which solar rays meet the surface at each latitude result in an uneven distribution of insolation and heating

Question 4

Define solar altitude, solar declination, and day length, and describe the annual variability of each earths seasonality

Answer 4

equator is 12 hours long, year round, 40 degree latitude, 6 hours difference in daylight between winter (9 hours) and summer (15 hours), at 50 degree latitude, 8 hours of annual daylength variation

Question 5

The nebular hypothesis

Answer 5

our solar system condensed from a large, slowly rotation and collapsing cloud of dust and gas, a nebula

Question 6

Milky Way Galaxy

Answer 6

include our solar system, as 400 billion stars

Question 7

Planetesimal hypothesis

Answer 7

process by which early protoplanets formed from the condensing masses of a nebular cloud of dust, gas, and icy comets

Question 8

A light year

Answer 8

9.5 million km

Question 9

Perihelion

Answer 9

the point of earths closest approach to the sun in its elliptical orbit, reached on January 3

Question 10

Aphelion

Answer 10

point of earths greatest distance from the sun in its elliptical orbit, reached on July 4

Question 11

Fusion

Answer 11

process of forcibly joining positively charged hydrogen and helium nuclei under extreme temperature and pressure; occurs naturally in the thermonuclear reactions within stars, such as our sun

Question 12

Sunspots

Answer 12

magnetic disturbances on the surface go the sun, related flares, prominences, and outbreaks produce surges in solar wind

Question 13

Magnetosphere

Answer 13

earths magnetic force field, deflects the solar wind flow toward the upper atmosphere above each pole

Question 14

Electromagnetic spectrum

Answer 14

the spectrum of all possible wavelengths of electromagnetic energy produced by the sun

Question 15

Wiens displacement law

Answer 15

all objets radiate energy in wavelength relate to their temperature , hight energy hight temperature, low energy Leo temperature

Question 16

Thermopause

Answer 16

a zone approximately 480 km in altitude that serves conceptually as the top of the atmosphere; an altitude used for the determination of the solar constant

Question 17

Insolation

Answer 17

solar radiation that is intercepted by earth

Question 18

Solar constant

Answer 18

is the average insolation received at the thermopause when earth is at tis average distance form sun

Question 19

Subsolar point

Answer 19

the only point receiving perpendicular insolation at a given moment

Question 20

The suns delineation

Answer 20

is the latitude of the subsolar point

Question 21

The suns altitude

Answer 21

is the angle between the sun and the horizon

Question 22

Declination

Answer 22

the latitude that receives direct overhead (perpendicular) insolation on a particular day

Question 23

Analemma

Answer 23

8 snapped path represent daily marking of the sun declination, which is the latitude of the sebsolar point, can locate any date

Question 24

Daylenght

Answer 24

the duration of exposure to insolation

Question 25

Revolution

Answer 25

orbit around the sun, 365,24 days at 107 280 km per h

Question 26

Rotation

Answer 26

24h, apparent deflection of winds and ocean currents, and produces the twice-daily rise and fall of the ocean tides

Question 27

Circle of illumination

Answer 27

the dividing line between day and night

Question 28

Axial tilt

Answer 28

23,5degree from a perpendicular to the plane of the ecliptic

Question 29

Plane of the ecliptic

Answer 29

a flat surface intersecting all the points of earths orbit

Question 30

Axial parallelism

Answer 30

unchanging axial alignment , with Polaris directly overhead at the north pole throughout the year

Question 31

Sphericity

Answer 31

oblate spheroidal shape lit by suns parallel rays; the geoid, shape of earth, spherical shape

Question 32

Tropic of Cancer

Answer 32

he parallel that marks the farthest north the subsolar point migrates during the year; June solstice

Question 33

Tropic of Capricorn

Answer 33

the parallel that marks the farthest south the subsolar point migrates during the year; December solstice

Question 34

Arctic circle

Answer 34

southernmost parallel that experiences a 24-hour period of darkness, same for antarctic circle

Question 35

March equinox

Answer 35

the circle of illumination passes through both pole, so that all locations on earth experience a 12-hour day and a 12-hour night, same for September equinox

Question 36

Solar cycle

Answer 36

is the periodic variation in the suns activity and appearance over time, 11 years periods of sunspots activities

Question 37

Solar minimum

Answer 37

a period of years when few sunspots are visible

Question 38

Solar maximum

Answer 38

a period during which sunspots are numerous

Question 39

Solar flares

Answer 39

magnetic storms that cause surface explosions

Question 40

Prominence eruptions

Answer 40

outbursts of gases arcing from the surface of the sun

Question 41

Net radiation

Answer 41

the balance between incoming shortwave energy from the sun and all outgoing radiation from earth and the atmosphere

Question 42

seasons varies because of what

Answer 42

with the suns altitude, the suns declination, the daylength, and the earth revolution in orbit around the sun, its daily rotation and its tilted axis, and its sphericity

Question 43

dawn

Answer 43

the period of diffused light that occur before sunrise,

Question 44

twilight

Answer 44

the corresponding evening time after sunset