Astr

onom

y C

hapte

r 5

•T

here

are

thre

e m

ain

devic

es for

gettin

g

radia

tion fro

m s

pace.

•O

ne is the tele

scope.

Secon

d is a

radia

tio

n s

ort

er

att

ached t

o t

he t

ele

scope.

Third a

re d

ete

cto

rs f

or

cert

ain

types

of

radia

tion.

Galil

eo h

ea

rd a

bo

ut

a t

ele

scope

invente

d b

y H

ans L

ipp

ers

hay

We g

ath

er

light

with

a lense

or

a

mir

ror.

Then y

ou g

ath

er

the info

.

•F

irst you w

rote

it dow

n.

•19

thcentu

ry y

ou took p

hoto

gra

phs.

•T

hen tv

cam

era

s.

Today C

CD

’s

•C

harg

e c

ouple

d d

evic

es.

A lens b

en

ds lig

ht

to a

poin

t calle

d

a f

ocus

A r

efr

acto

ry tele

sco

pe h

as t

wo

lenses.

Larg

est

refr

acting t

ele

sco

pe in t

he

worl

d,

40 inch a

t Y

erk

es

observ

ato

ry in W

isconsin

.

Leand

er

McC

orm

ick a

t U

VA

The o

ther

main

type is a

Reflecting

tele

scope.

•T

his

is a

concave m

irro

r m

ade o

f gla

ss

coate

d w

ith s

ilver

or

alu

min

um

.

•

Ne

wto

n inve

nte

d t

he f

irst one in

166

8

Larg

e c

onca

ve m

irro

r be

nds lig

ht

to

a p

rim

e f

ocus.

Todays

tele

scopes a

re 8

to 1

0

mete

rs a

cro

ss.

The K

eck t

ele

scop

es o

n M

aun

a

Kea u

ses 3

6 h

exag

onal m

irro

rs

each b

ein

g 1

.8 m

ete

rs.

Atm

osphe

re m

esses u

p o

ur

vis

ion

4 w

ays.

To p

ick a

site y

ou n

ee

d.

•C

lear

75%

of th

e tim

e.

•D

ry w

ith h

igh a

ltitude.

•N

o lig

hts

aro

und d

ark

sky.

•A

ir s

hould

be s

teady low

turb

ule

nts

.