Document 64296

THE SMITHSONIAN INSTITUTION
WARNING:
FACT SHEET
The Smithsonian Institution is a nlu~,¢um, education and research complex
of 17 nluscu111~ and galleries, and Ih¢ National Zoological Park. Fifteen musetnms and galleries are located in Washington,I).(’., two are in NewYork City, and
lhc Nadonal Zoo is in Washington. "l~n of the museumsand galleries are situated on ~he Nadonal Mall between Ihe tLS. (’apiml and Washington MonumenL
One of the world’s leading scientific research centers, the Institution has
facilities
in eight slates and the Republic of Panama. Research projects in the
arts, history, and science are carried out by the Smithsonian all over the world.
The new National Mt~scum of the American Indian is scheduled to open on
the National Mall in 2002. The centerpiece of the museumis the priceless collection of Native American artifacts
~ransl~rred to the Smithsonian from the
Museum of the American Indian, Hcyc Foundation (New York). The New York
exhibilion facility - the Hcye Center of II~c National Museumof the American
Indian opened Oclober 30, 1994 in lower Manhaltan.
Anolher new museum, the Nadonal PosIal Museum, is Iocalcd near Union
Station on Capitol Hill. Devoted to the history of the U.S. mail service, the
museum houses the world’s largest and most comprehensive collection of its
kind, with more than 16 million stamps, covers, and artifacls.
Onlyfor useby children over8 yearsold. Onlyfor
use under the supervision of an adult. DONOT
VIEW SUN THROUGHIELESCOPEAS SERIOUSINJURY MAYRESULT!
CAUTION:
Readthe instructions before use, follow themand
keepthemfor reference.Storetelescope
set out of
reachof smallchildren.
ITEM#1144
AGES8 & up
SMITHSONIAN
50x Telescope
HISTORY
James Smithson (1765-1829). a British scientist,
drew up his will in 1826
naming his nephew. Henry James Hungerford. as beneficiary. Smithson stipulated that should the nephew die without heirs (as he did in 1835). the estate
would go It, the United States tt, ft,und "’at Washington, under the name of the
Smithsonian Institution.
an establishment for the increase and diffusion of
knowledge..."
On July !, 1836, Congress accepted the legacy bequeathed to the nation by
James Smithson, and pledged the faith of the United States to the charitable trust.
In 1838. following approval of the bequest by the British courts, the United
ql~l~.~: r~.~’PivPH’~,,~_ithson’s estate - bags of gold sovereign,~
of $515,169. Eight years later, on August I O, 1846. an Act of Congress signed by
President James K. Polk, established the Smithsonian Institution in its present
form and provided Ibr the administration of the trust, independent of the government itself, by a Board of Regents and Secretary of the Smithsonian.
DEAR CUSTOMER,
NSI is the manufacturer of this kit. If we madean error and left something out of this set, or if something is
damaged,we are sorry and wish to correct our error. Please do not return the set to the store where you
purchased it, or to the Smithsonian, as they do not have replacement parts. Instead, write us a letter giving us:
1. Dateof Purchase
Purchased
2. Where
3. ModelNumber
4. Name
of Set
5. BriefDescription
of Problem
6. Sales
Slip
Wewill do our best to satisfy you.
Quality Control Department, Natural Science Industries, Ltd.
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PRINTED IN CHINA
ITEM NO. 1144
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910 ORLANDO
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Parts t)t" YourTelescope
()bjectivc I.ens Lid
2 Objective Lells
3 i~ens Hood
4
’rclcscopc Tube
5
Bracket
Knob Boh
7
Tripod Legs
8
Focusin~ Tube Holder
9 t:ocusin,~
Tube
10 Eyepiece
II Eyepiece lad
I. ~ I:ocusi]~g Knob
13 l)iagonal Mirror
4
Care of Your Telescope
Your telescope should hc kcpl away from dusl and moislllrc. I IJlC Ic~lSCS~cl
dirty, blow any dust parliclcs olT before cleaning. Clean the lense~ with a moistened lens tissue. Alwaysstore your telescope in the box whennot in use.
How MuchPower: Choosing the Eye I,ens
Powerrefers Io Ihc ability of a telescope Io enlarge an image, or. in cflccl, bring
il clo~cr to the viewer. Amountof magnifyingpoweris signified by a numberfollowed by an X (read "power"). So if you view an old, col at 50X. you arc seeing
it as if you are 50 times closer to thai o~jccl. Poweris calculated by dividing lllc
focal length of your tclcscope’s otLjcctive lens (probably indicated on the Ibcus
tube) by lhc Ik~cal Icnglh ot" the cyc lens you select. The focal length of the eye
lens is usually indicated on the eyepieceitself.
500mm
(focal length of objective lens)
Wayis much brighler. ’lb set, Ihe Milk~ Wayyou need to go where the sky is vcr~ dark when
there is no moonin the sk3. There are patterns of hright sial% to he found here too. First lind
the "Big Dipper", the hrighlesl stars of the constellation Ursa Major. The two stars at the front
of Ihe houri of Ihe dipper poinl 1o Polaris, the Norlh Stal: Then I~flloxv Ihe arc of the handle to
Arclurus, and then spike to Spica. High overhead look I~n" the large summerIriangle: Vega,
Deneb, and Altair. Antares is a reddish-looking slat in the soulh, parl of lhe conspicuous constellation Scorpius. Be sure Io sxveep lhe summerMilky Waywilh hinoculars to lind dozens of
rich star cluslers and fuzz3 palches of nebulosily (glo~ving gas cloudsL Note, Ihe ecliplic, the
path of Ihe sun. moon and phmels is low in the nighltime sky and high in the daylime sky in
the summer monlhs.
FALL
= 50X (power)
Example:
lOmm
(focal length of eyepiece)
’l"hc Ior~gcr the fl~cal length of the eyepiece, the less the magnifyingpowerof the
Iclescope: the shorter the focal length, the greater the power. So whenyou sclccl
eye lens to inscrl into the diagonal prism, you’re really choosing what magnit3,ing poweryou wish to use for obserwttion.
Helpful tlints for Setting Up YourTelescope
1 ) Unpackthe tripod fl’om the box. Next, s~and the tripod up verlically
by pulling Ihe leg extension anct sprcadirlg Ihe legs apart fully.
2) Slide the telescope bracket (5) arKl adjusl Ihc holes.
3) Removethe lens lids ( I 1 &1 ) from the eyepiece and the objective lens
(10 & 2).
WARNING: DO NOT VIEW SUN THROUGH TF.I,ESCOPE
AS SERIOUS INJURY TO EYE MAY RESUI/F
17
Observing Astronomical Objects Through Your Telescope
l) Glance through the main telescope% cycpiccc{ I{)) For your o~cct. (Note:
mayhave to alter the angle ol" the telescope slightly.) The o~ject will n~ost likely seem
to beblLIrry at this ~tage,hul lhal i~ Ilorlllal. Youare just trying to get the
o~ject in the viewing field of your telescope lens. ()nee you have accomplished
this lask, fitsten the knobboll (6) Io keep Ihe accuracy of your lelescope steady.
2) Nowat{iust Ihe focusing tube (9) by turning the focusing knob (12) slowly
back and fl~rlh unlil Ihe blurred o~jecl becomesprecise.
3) If you are going to be looking through the telescope Ik)r a short period of time,
you can insert tile eyepiece (10) directly into the focusing lube (9). To be
comfortable whenusing your telescope for longer periods of lime, place the diagonal mirror (13) inlo the Ibcusing tube (9) and Ihe eyepiece (10) inlo the
nal mirror.
WINTER
SOUTH
The~.linter ~,k.,, 1 b, dominak’d
hy tl]~ bright constellation()rion. the hLml~r,with hi~ prominent
h~ll ~ )
three equally N~aced~tar~. Notethe I’ill~
of blli~ht Marx~lilrolitldhl~
()l’iOl]: Ri~el, Aldeharan,
(’apella. (’a~tor and Pollux. Pl’ocyon. and Sh’ill~ (the brightest M[Lr in the n]i~i]tthne ~ky).
Betel~eu~e
in the middle.l’i]i~ I~,q~ i~ ~Otllethl]e~ called the "’Winter Ilex~L~On."Onceyoucanidenfify
the~e ~taF~ you ~’all
work yOllf
~~ OLit to Lhe ~Llrl’Olllll]hl~
con~tellathm~.
Note. the cc’lq~tk’,
path of tile sun, inoon,andpmanet~
i~ highin the nightlhne~ky andIo~ ~11the d~l)’thlle
~ky
the
in the ~’il]-
Overview nf the Snlar System
By definition, our Solar Systemconsists of the Still, nine planets, their moons,
and an ut~k~ownnumber of asteroids (small rocky bodies) and comets (small
bodies of dust and ice). The inner planets, Mercury, Venus, Earth, and Mars, are
similar in that they were lbnncd from dense, rocky materials, unlike the outer
gaseous planets, Jupiter, Saturn, Uranus, and Neptune.Pluto is the oddity, a small
rocky-like planet on the outskirts of the Solar System. Most asteroids are located in orbit (the path of one body circling another) between Mars and Jupiter.
Beyomlthe orbit of Pluto, comets can be Ibund in the Oort cloud (a band of
comets). Occasionally, the pull of the Sun’s gravity (lk~rce of attraction between
two bodies) brings comets tracing exaggerated elongated orbits into the inner
Solar System.
Icl"
/
!. Our Solar System In Depth
A. Mercury: Taking a Clnser Lnnk
AlthoughMercuryis the fourth-brightest phmct, finding it in the sky can be difficult even whenyou knowwhere to look. Bccauxcit is the closest planet to the
Sun, fromour viewing platform it is always in the same part of the sky as the Sun,
visible only right after sunset or right bel’ore sunrise. This meansit is close to the
horizon and our view is shrouded by the thickest part of the atmosphere (the
gaseous envelope surlout~dit~g the [~arth). Circular depressions called impact
craters, caused by debris hitting the surfi~ce, cover the entire surfitce of Mercury
making it difficuh to distinguish it from the Moon.The Mercuryimpact craters
do not appear as deep as the Moon’s, and the ring of ejected material around each
crater is closer in. Mercury’s surface gravity is over twice that of the Moon,
resulting in shallower craters, and preventing debris from travelling far from the
impactsite.
. - ¯ ’.-.-.-...
’" ~I ......
’,.....
¯ " ,’-:
The Milky Way:Wheuyou see the Milky Wayin the night sky. you maywell
see howit got its uame.Throughoutthe ages, this band of lighl has also been
referredas a river. Wenowknowthat this bandof light is made
of stars leo far
awayfor our eyes to distiuguish Clio point of light fronl another. TheMilkyWay
is a spiral galaxyof about 300billion stars, resemblinpa flat disk wilh a slight
bulgein the center. ()ur Solar Systemis in a spur of’oneof the spiral armslocaled about 2/3rd of the wayout from the center of the galaxy. The band of light
seen across our sky is our viewof the plane of the galaxy. In other words,if our
galaxy were a pizza, fgomour slice of peppcroni, wewouldbe looking at the
crust. Therifts of dark patchesthai wesee iu the Milkywayare uol holes opening up to the other side, but dusl and debris blockingour view. Thebright stars
seen in these dark patchesare closer in to us than those in the arms.
.’
¯ " : ’: " -, ,- " :-: :--:- ~--. ~...~~’..5....
/
.... ;.,, .... ....
B. VENtJS: "l{ikiug
a Closer l~ook
Will] a nlaxiintlln nlagnitudc
iiil~o~
The Andromeda Galaxy: Located in the constellation
Andromeda, between
Cassiopeia and Pegasus, is the clongalcd smudge of the Andromeda Galaxy.
Even with a nice backyard telescope, you will see only ,’~ smudge. Just imagine
that the light left that galaxy almost 3 million years ago and is ouly nowreaching
our eyes. For those of tlS in the Norlherl] Henlispherc. with I]orma[ eyesight, the
AndromedaGalaxy is the furthl3sl objc¢l visible wilk Ihe unaided cye, ]lid the
only visible objectthal is lie] parl of our OWll Milky WayGalaxy,
(apparolli
brighti]ess)of-4.7.VciltlS
brighlor lhan Iho noxl hrighl~l
planol. Jupilor.
Thougll known a~ lhc
~VOlliilg afler suns~l. WhenVclitl~ i~ clo~c to the horizon, it can appearto datlco
and ~hilllnl~r thi’ough lho almo~phcricha/o. and i~ oflon nli~lakon for a UFOhovel’in 7 clo~c to the horizon.
PlanetaryNebula:Believedto be qjectcd gas from dyingred giant stars, planetary nebulas generally appear as rings or hourglass shapes, looking mtich like
planetary disks under low n]agnification. Examplesinclude the Ring Nebulain
Lyra and the Helix Nebulain Aquarius.
Supernova
remnant:
Ancxpaliding shell of gas reruainiilg after a violent explosion during the final stages of a star’s evolution. Example.~include Ihc Crab
Nebulain Taurus, and the Veil Nebulain Cygnus.
Galaxies:Defined as a concentrated assemblyof gas, dust and stars. Galaxies
comein various shapes: spiral, irregular, and elliptical. Examplesinclude the
WhirlpoolGalaxyin CanesVenatici andthe Pinwheelin Triangulum.
¯ " . ." ¯
I
’ :.~ ....
’: ~ ......
...-7-, , " ....
Star Clusters: Group of stars located closely together, helieved to share a comIllOi] origin, Star clusters can have thousands of stars or only a l~w, Examples
include the Pleiades in Taurus and the Beehive in Call¢er.
...-__,
....
i,.
., .~.~~~~-~
i---~,.
. ;.,..
-..
I ..,~.~:. --,-- -_--~--.~Z"-, - .... .~ .’~
~’~......
L,
I. ....
¯¯
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-
,
.
! ......
i" .-"- "t,. \.’.: ’.., ~L.A
’.:’-.,:.......
~
-.-~., ’ ,. ¯ .. i ."..:.7..~.~l
’~i.; :"4¯ - hi
.’~ ..’-t
t ......
.//
....
~
":
.
,,
’"
".."" ’.
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,--:--~
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Globularclusters: Largergroupof hundredsof thousaudsof stars clustcrctl
together andbelieved to share a common
origin. Examplesinclude the Great
GlobularClusterin Herculcsandthe M4in Scorpius.
, , ~ ......
¯
~
" ¯ ~fl",
,.--’., ..... .. ~
Apparcnl
lialh ill" Vi’nlls ill relationto the background
stairsat one-day
intervals.Themotion
is shnihir
to thaiof Mercury
eXeClll
Vl~llllSnllll’~snlorl~slowly
]lid lher~2trlil~rildl~ loops
arl~flitflier aparl,
MultipleStars: Two,three or morestars circling aroundthe samecenter of gravity. Moststars that appearto the nakedeye as a single pointof light are actually
multiple stars, andmayrcquirc a telescope to see the nunaerouscompanions.
Sirius in CantsMajoris a double, Rcgulusin Leois a triple, andCapcllain
Aurigais a sextuple.
Polaris is currently our NorthStar because
il is len)porari]y locatedalmos[dir¢clly aboveI~arlh’s Norlh Pole. ()nee you hwalc Polaris, you hawfound norlh,
m~~ouone of your cardinal diF¢clions. WhileIookin~ al Polaris. cast will bc
your riBhl, w~ston your I~l’t, andsouth~il] bc behind~ou."l’hcsc diicctiolln
b¢ imporlanl for findin B your wa~through the niBht sky, maKh)
B the Bi~ I)ippcr
lit1 hlvaJtiahIc+otlidcpost.
Before
IIl()V~ll~. t)ll, lakest)me1~111~1() illlprcsn ~()tlr falllil~andfriends.
C’on~iclcr
(l~c~an~ular)
height
ofP(~larh
ahoxcthehorizon.
Remember
lhalPolaris
ix totaled
ahnosl
dircclIX
ab(wclhcN()rlh
Pole.
So,
wcrcal lhcNorlhPole,Polaris
wouldbc dirccll
over
xour
head.
Chances
arc,
X
liftsin nollhccasewhereXouarcnow.So,wherearcXou?Polaris
andxour
canhelpXouIi~urc
nomcof XourIocalion.
A I’islheldal armsIcn~lh
mcaxu~cx
aboultO dc~rccxfrompinkX knuckleto thumbknuckle.If Xou wcrc in
Washin~lon.
I).(’.,
ilwouldlakefourI’isls,
oneslacked
onlopofIh¢olhcr,
reachPolaris.
It.jusl
xohappens
lhalWashm~lon,
I).(’.
isncarl
norlh
X ~0 dc~rccs
lalilud¢,
mcanin~
4()dc~rccs
norlhofEarlh’s
cqualor.
IfX()uwcrcIurlhcr
perhaps
Fhwida,
ilwouldlakeonlX lhrccfisls,
~ivcor lakea I’in~cr.
BX mcasurin~lh¢hciBhl
of Polaris
inthiswax,Xoucanrou~hl
xournorlh
I~IiX dclcrnfinc
ludc.If XouwcrcbelowlhcEarlh’s
¢qualor,
Xouwouldnolfinda Soulh
Slar.so dclcrminin~
xoursoulhlaliludc
wouldh¢ muchlou~h¢~.
When
you searchthe northern part of the sky, the only changesyou will find are
Ihc positions of the constellations as they appearto movearoundPolaris. If you
canimagineIhJn part of lhc sky an an umbrella,Polaris wouldmarkthe lip at the
lop. As youlwirl lhc umbrella,lhc slats closer Io Polarin movearoundin a li~hlcr
circle.
The further awaythe star is from Polaris, the larger the circle, until eventually the
slar falls hch)wthe horizon, appearingto rise in the Easl andset in Ihc wcsl. The
Marsthal fall belowlhc horizonare consideredseasonalconstellations. "[’hey are
only visible at ccrlain times of lhc year, andIhc particular seasondclcrmincshow
E TAKIN(; A CI,OSERI,OOK: You can find many sky objects with the
unaided eye. Before you look. remember to allow your eyes time to adapt to
whatever darkness is available. Evenif you arc in an area affected wilh light polItllion, somestarry o~jects will he visible after you stand in the dark Ibrabout I0
IllilltlleS. The further awayfrom the lighls, the morelime your eyes need to fully
adapl~around 20 minutes in a nice dark sky environment. Cerlainly if the Moon
is up, look while you are waiting. The brightest slars and planets will become
visible first; these are excellent guideposts in their ownrights. Eventually, the
dimmer stars will come inlo view. The darker the environment, the more stars
you will see. If you arc in a nice dark sky, you will be treated to the Milky Way
and some nice deep sky objects as well. A good star map will show you where
to find deep sky o~jects, manyof them visible wfih the unaided eye as nebulous
palches.
Througha telescope, Venusappears as a featureless white ball that goes through
phases similar to the Moon’s. As you lbllow these changing phases, you maysee
a dark atmospheric ring oudining the plancl. Notice also thai the slim banana
shapedcrescent appears muchlarger than its fuller than half bul not quite full gibbous phase, suggestingthat duringits crescent phase, it is closer to us, while its
gibbous phase occurs whenit is far away, on the olhcr side of the Stun.
C. MARS:Taking a Closer
Marsis our first outer phmet.It is reddish brownin color. When
the Earthcomes
betweenMarsand the Sun, Marsis at opposition (opposite the Stm in the sky).
At these limes, Marsis very close to the Earth and appears bright. WhenEarth
andMarsare far apart in their orbits, Marslooks muchfainter. Since the orbit of
Marsis elliptical (owd) someoppositions are closer than others. In one month,
Marsmoves against the backgroundof stars on the average aboul I-I/2 hamls
dircction again to continue along its easterly journey. This is called retrograde
mntion. If you could see the Solar System from above, you would scc Earth
movingfaster on the inner loop, passing slower Marson the outer loop. Mars
appearsas a disk througha telescope -no longer just a pinpoint of light, as it
looks to the unaidedcyc. Somesurlktcc detail becomesvisible, such as the darkcr regions and the white polar caps. Unfnrttmatcly.as Marsnears the sun, solar
radiation triggers massivedust stormson the planet, so thoughthis is the ideal
time to look at Marsbecauseof its close dislance to Earlhand the Sun, it is the
worst time tk)r detecting any surface dclails. Ducto the presence of iron oxide,
the rocky surface of Marsis the color of red clay. There is no atmosphereon
Mars:the surface gravity was not strong enoughto hold onto the gasscs during
the cooling period. Nor is there any surface water, and what water there maybe
on Marsis frozen beneaththe north and south axis or poles, covered by dry ice.
D. STARS:By defivfition,
a star has its own nuclear power source, and is capable of producing its own light. Stars come in many different colors. Yon will
notice blue, orange, red, and yellow stars. Our own star, the Sun, is a middleaged average yellow star, called a main sequence star. Average stars begin their
life in a cool cloud of gas and dust. As the star consumes its own matter, it
Apl)arentPathof Marsin relalion to the hack~roan(I
stars at one-day
interw|ls. Themotinn
right to left (west to east) on the average, with relrogra(It, <easl to west) motionxvhenthe inner
plane! (Earth) comeshetweenthe outer phlnel (Mars) the Sun.Note,Ihis means that d aring relrograde Marsis at "npposilion," opposite the Sunin the sky: nverhead,’it midnight.
D. JUPITER: Taking a Closer Look
Jupiter is generally hrighlcr than the brighlest fixed star, but not as bright as
Venus. Jupiter is visible fi’om somewhereon Earth fi~r I I out of 12 months of the
year. It moves slowly across the sky, and once I~)ulld is easy to track.
becomes part of the main sequence, until gradually becoming a red giant or
supergiant, then finally ending ils life by shrinking to a white dwarf. A very massive star at birth quickly reaches its hot stage, becoming a white or blue-white
star, collapses to a white dwarf, and perhaps further collapses into a neutron star.
or even further inlo what is called a black hole. Whenyou look into the night sky,
the blue white stars are the youngcsl, hottest, and brightcsl. The red slars are
cooler, older, and generally dim. Main sequence stars range fiom cool red to hot
blue-white. Though not the norm, you can still find bright red stars, and dim
white stars. Also, many supergiants, because of their location in ~he universe,
look like ordinary stars from our viewpoint.
E. FINI)ING DIRECTION: Learning yt)ur way around the sky can be easy
you get to know a few simple guideposts. I+ealn the brightest stars in groups
(such as the Winter Itcxagon, the SummerTriangle. etc.) and a few t)l" the most
prominent constellations
(()rion, the Big Dipper. Scorpius, etc.). You don’t
to know the whole sky to find your way, as long as you know a few roll-able patterns that can be found easily. ()no of the most famous guideposts, for Northern
Hemisphere observers is the Big Dipper.
Using the pointer stars of the Big Dipper, draw an imaginary line through
the sky until you reach the first bright star, Polaris, our North Star.
THIS DISTANCE
EQUALS YOUR
LATITUDE
Apparent
path nf Jupiterin relation tn the background
stars at five-day intervals. Themoti(ms
of all of the oaler planets are similar tn the mntionnf Mars,excepllhe speedsare progressively sh)werand the retrogradeInops are progressivelycloser Iogether.
With ordinary binoculars, Jupiter appears as a yellow oval disc with its four
brightest (Galilean) Moonsclose by. Just how many of the Moons are visible will
depend on each of their locations in their orbil around Jupiter.
4
--YOUR
¯
HORIZON
NORTH
From:
"Stars
andPlanets",
byW.S.Kals.~1990
byW.S.Kals.Reprinted
withpermission
of SierraClub
Books
13
Earth’sOrbit
:
Earths O, rb~t
... ~
o~ec.tion o~Sun"~’~-~ .
Sun
Total
Annular
Partial
They mayhe all on one side, spread out equally, in transit (passing in front of
Jupiter), or hiding behind the planet. A small telescope will reveal some of
Jupiter’s cloud bells. Large Iclcscopcs reveal cloud slr’ucturcs of light zones and
dark bclt~ ctossitlg Jupiter’s cqualor, as well as irregular ~pots alld streaks. From
north Io south, Jupiter changes in appearance. The North Polar Regionis the least
dclailcd. The Norlh "l~mpcratc Bell is bordered I~y red colored whirlpools. The
Norlh Tropical Zone coulains the lighter level of clouds and appears bright white.
The North I~tlUatorial Belt diH~lays hurricane wind #uxts of over 355 milc~ per
hot. movingin difl’crcul directions.
E. Saturn: Taking a CI.ser
(;chorally, Salulll looks like a bright first magnitudestar of no particular color,
is never as brilliant as Venusor Jupilcr, and its brightness will cllangc depending
on how muchvisible sunlighl is rcflcclcd off ils rin~s.
," ’ track of Saturn
~ Kccptng
is easy: it i’cmains in the same area of the sky for months, movingabout a hand
in oucyear. It is the l’arthcnt planet l’r(m] the sun thai wc caneasily scc with the
unaided cyc.
.... ~:...
¯ .b,:..
(Left) Courtesyof. "Facts on Fde". 3rd Ed~hon.Market HouseBooksLid , Aylesbury. Untied Kingdom
(R~ght) Courtesy el "Skywatch Eyes-OnAchwhesfor Gelling Io Knowthe Stars"¯ Peter Lancaster-Brown.Adetburgh, Suffolk, England
11. Overviewnf the evening sky.
A. OUR VIEWINGPI.ATFORM: Whcu looking oul into the night sky,
rememberthat it iN only tron~ our special viewing platlorm that the sky looks as
it does. Earthis a small planet, circling a very ordinary star, in.just oneof many
galaxies groupedlogclher in a universefilled with galaxyclusters and dark mattee. Keepin mindthai the viewis dil’fcrcnl from everyspot in the universe.
B. CONSTEI,i,ATION:A constellation by definition is a portion of the sky
separated from other areas by agreed upon boundaries. Every culture that we
knowof looked up al the sky and namedareas after things that were either familiar’" TM ..... ; .... , ..... or,,, ~ ....... ’ .... partof their .... ~,,r,- M,,,’~cultures
named
star patterns, the forerunners of our modern constellations. The Arabs mostly
namediudividual stars rather than groups of stars. SomeSouth Americancultures
cvcn named the dark patches in the Milky Way. As you can imagine, there were
manynames for specific areas in our sky. In 1930, an association called the
International Astronomical Union, an organization responsible for establishing
international standards and namingastronomical objects, divided the sky into 88
specific boundaries, and assigned them official names. Westill use these names
today. Every part of the sky falls within one of these 88 boundaries. Think of
these divisions as slate lines on a mapof the United States.
C. ASTERISM:
An asterism is any generally accepted group of stars not off’icially namedas one of the 88. Twoexamplesare "’The Big Dipper," which is part
of the constellation Ursa Major, and "’The SummerTriangle," borrowing stars
frorn three official constellations, Cygnus,Lyra, and Aquilla.
. ..
¯ .’ .." ,’
:~...: ./..
.
. .... ~’~.-~.
.,,.....:..,.
¯ ...,. ,-. ....
~.:.-
.&..!
..,..
..,:, ":..--~. .,. ~ . - .,. , ,.,
<’
~ -~ ._
.....
, ’ ~. ¯ .
,"....
I’: ,- ’ , ¯ ¯ , --:;~ .. ~ ,,...,
: z
Apparenlpalh of ~alurn in relatioa to the hat, kgroundstars al five-day i~tervals. Note, SalurB
movesabout half as I~r betweenrelrograde loops as Jupiter. The retrograde loops are a little
over one year aparl.
Saltlrn’s rings arc nol really wilhin rangeof slandardbinoculars. However,when
viewedthrough a small telescope, they becomevisible as humpson either side
with visible gapsseparating the rings. Depending
on whereSaturn is in its 29
year orbit, the rings can bc seenanywhere
from edgeon [o fully open.Twiceduring Saturn’s orbit, the rings will bc edgeon and disappearfrom our view completely. Close up viewsof Saturn’s rings showhundredsof ringlets, somebraid~d, wflh small shepherdingmoonsdividing the rings sections, which are made
mostly of ice crystals ranging in size from a t~w centimeters to a t~w meters.
Like Jupiter, Salurn is squashed
at the poles, has bandedrings, and large white
hurricane storms.
~a|LIrBas ~eeli Illi’otl~li
arrialettr I~leseope
Whena lunar eclipse occurs, llOl everyone on Earlh wilt be able to see it. The
ffloon must be above your horizon. So if the moonis full at 4:02 p.m. ES"I2 and
this just happens
to he a lime whenthe nloon is belowyotir horizon, yotl will ilOt
see the eclipse. However,SOl~ooneon earth will, and with clear wealhor, yotl will
still be trealed Io a filll moonthat evening--;jttsl noi an eclipsed one.
A lunar eclipse is entirely safe to watch with the unaided eye, hinocuhirs, or
a telescope.
E Uranus: Taking a Chiser I,ook
Uranus is visible to the unaided eve only under exceptionally clear conditions.
and even then it never gels brighter than a faint 6th magnitude star. However,
once you find [Jranus, her very slow movcmenlIhrough the slar field should keep
you on lrack lbr manyyears.
Apparent path of Uranus in relation to the hackground stars lit ten-day intervals.
Note,
Uranus movesso slowly that its retrograde loops overlap. Also its orhit is closely aligned with
the earth’s orbit, so the loops don’t sl~llld Olll well in a diagramlike this.
Onceyoufind Urantlsin tile night sky, a smalltelescope
will tl’ailsfol-rll ils Sl~ll’like inlage into a small greentTatut’oless disk. WatchI]lr severaleveningsto see
UralltlS nlovethrouThlhc hack~l’ound
stal’~. []veil lhrotlgh the lar+0st lele+copos
and probes, a green l~’attlroloss disk is all we sco. Hnwevcr,these largo telescopes
arc necessary to spol i~er 15 salclliles, all smaller than Earth’s Moon.
G. Neptune: Taking a Closer I,ook
Neptuneis till 8th niagriilude binocular object, arid looks Iikc a bltie star. With
patience, over manynighls, you can see Ihe plancl moveagainst the background
stars. Youwill need a good-sized telescope Io view Neptuneas a disk or Io see
its largest moon,Triton.
6
Solar Eclipse
A solar eclipse occurs only whenthe Moonis directly bclweenthe Earth tllld Still.
Because the sun is 400 iimes larger than the moonand the moonis 400 times
closer to the earth, the sun and moonappear to be the same size. Tiffs allows the
nloon at times Io completely cover the sun during an eclipse. As the
shadow
sweepsacross the earth, allyOile located in its palh will see the nRiOll
Ct)VCl’ [he ~tlll, tilid lt~r tip Io seV~ll milltliCS, blockits light. If you alo Oll Itlo OtllOr
limiis of tke mOOll’~~htlOOW,yOtl will wilnossa parlial eclipse, rind ~o~only partial coverage of the Still. Nol all solar eclipses are equal. The Moon’sorbit
around the Earth is oval, or elliptical. The distance the moonis from the earth
will affect its apparent diameter. The closer the moonis to the Earth, the larger
the moon’sapparent diameter; the farther away, the smaller. Solar eclipses that
occur whenthe moonis closer to the earth will be longer, up to about seven minutes. If the Moonis farther fiom the Earth the duration of the eclipse will be
shorter, or if it is sufficiently far fi’om the Earth it will t~il to completelycover the
sun. An "annular eclipse" occurs when a ring (or annulus) of bright sunlight
remains surrounding the disk of the Moon.If the Moonis not centered on the disk
of the Sun the eclipse will be partial. Even a total eclipse starts and ends with a
partial phase as the Moonslowly covers and uncovers the sun.
Wheneverany part of the bright white disk of the sun is visible it Call damage your eyes. Do not look at a partial or annulareclipse, or the partial phases of a total eclipse, withont specially designed eye protection.
The brightest slars and planets becomevisible during a solar eclipse, and anirnals
think it is lime lbr bed, nlis/aking the darkness lbr llight. WhenIhe nlooll nearly
covers ihe stln, righl belbre or after totality, bright beads of lighl, knowll as
Bailey’s beads and thc diamondring effect, are visible. These are places whcre
the Sun shines through the Moon’s craters and willeys. During a total solar
eclipsc, wc can sce the Sun’s dazzling corona or outer layer.
Total solar eclipses can occur up to 5 times a year, but seem rare because 300
years can pass before one is seen in the same location again.
11
As the MoonCol]thltles travelling cotlllter¢lockwise arotll]d the F.arth, it soon
becomes
visible directly al’tcr StlllSet ~.IS a Ihin crescent, with its points hacktowards
Ihc easl. This phaseis called a w,.~i,g cresce,t.
As Ihe Illollth plogresses,lhe Moonmovesfl.lllher caslwardill Ibe lwjli~hl sky, growjng f;.|ller (or Waxing)
inlo a./)’r.sl qllarler Moo11,
;.I phase
we,,cu as a half ]jl M~.)oll,Ihe
weslern half.
As lhe Moonmovesfurther easl Ihrough the starry sky, growing Ii~ller
its u’,xi,g gibbous phase.
still,
look for
Oncethe Moonis./)dl, it will rise as the sun sets. The Earth is betweeuthe Moonand
StIll now. but the Moonhas only BoneIhloU~]l half of Jim phases. ~bout 14 days into
its cycle.
Still tlavclhng eastward Ihrough the starry sky, visible only after the Still has set, wc
begin to scc less of the stmlit surface of tbc Moon,a phase called the
Eventually, only half the Moonis lit again, but this time the other half or the eastern
half is lit, a phase called htst or third q,arter. ((~ucss wherethe sun is!) At this time,
it is well after midnight.
Waningthinner every night, we will eventually find the motto as a thin crescent, only
this time the points arc airncd west awayfrom Ihc sun rising.ju.st behind it in the cast.
This phase is called
Apparent
path of Neptune in relatiun
to the Ir.|ckgruund
stars
al ten-day
intervals.
I,ike
Uranus,Neptune’sretrogradeluops overlap.
Aside from Earth, Neptune is the bluest plzmct in the Solar System. Visible are
the Great and Small I)ark Spots in Neptune’s southern region, and an atmosphere
speckled with white clouds of methane ice.
H. Pluto: Taking a Closer I,ook
Telescopic views show an elongated
image, indicating
two bodies,
rather
than
OllC.
Eventually the moonwill bc m,wagain, lost in the sun’s ~larc, completing its monthly cycle. It is only during its ilew illOOli phase that the mooncannot be seen in the
sky, day or night, anywhere on earth.
l,unar Eclipse
An eclin,~e hi’the M~mI~lkes phlce when Ihc F, arth is lined up direcllv in between
the Sun and Moon. Whcu lined up perfectly,
the Earlh blocks the sun from shining on the moon. ()r another way Io think of it in that the moon passes through
the shadow Earth cants into space. For up to I hour and 47 minutes, you can see
this shadow slowly creeping across the face of the moon. This Earth shadow on
the moonis circular, providing early proof Ihal Ihe Earlh is round. An eclipse of
the Moon can only take place when the moon is full. However, because the orbit
of the Earth-Moon system around the Sun is tilled, a lunar eclipse does not occur
each time there is a full Moon. Generally, the fnll moon passes just above or
below the shadow of the Earth. This allows for various types of hmar eclipses:
total (as described above), partial (Earth’s shadow covers only a porlion of
moon), or penumbral (just skimming tbc edge, no visible bite, but some darkening of the moon). For total and partial eclipses, Ihc iiioon’s shadowy area is usually illuminated by refracted sunlight from earth’s atmosphere.
10
Apparentpath of Pluto in rclatiun lu the backgrnund
stars at ten-day intervals, lake Uranus
andNeptune,Plutu’s rctrugradeInopsuvcrlap, but unlike the rest of the planets, the orbit nf
Pluto is highly inclined to the earth’s urhit. Imaginesomeonewalkingslowly past ynuhalf way
acruss the rnom while you muve your head hark aud h;rth ab{mt once every sccnnd. The
motiunuf your headrepresentsthe mntionof the earth as we Innkat Pinto drift slowly past in
the distance. Theright-to-left drift is causedby the nmtionof the planet. Theluopingis caused
by the motionof the earth.
7
I. MOON:
Taking a Closer I.ook
The manon tile moon, the rabbit on the moon, what do you ~ce? What you will
not sec is nearly one entire half of the moon. The same side always faces the
Earth because il takes Ihe same amount of lime I~r the Moon to spin on ils axis
(one day) as it lakes
piclures
of the far
to rotate
side,
around Ihe Earth.
which looks quite
Spacecraft
difl~rcnl
arc needed to send
from our familiar
vision.
The
The phases of the Moon (A) and the appearaucc of the
Moon at Ne~, First Quarler. Full and Last Quarter (B).
Last Ouar,er
A
line:
the division
surface of the moon. See if you can find
closely al the
bclween sunlight
any of these
features
and darkness
Waxing Gibbous
~
.,.--~
Earth (~,F
1 (0 days)
~~2 {7 days)
on the
~
Gibbous
Crescent
(14 days)
(~-~4 (21 cays)
First Quar.er
Courtesy
of: "’Skywalch:
Eyes-On
Activitiesfor Gellir}gto Know
trio Stars.PeterLancastnr-Browrl.
Adelburgh.
Suffolk.England
HI,ION
Quarter
Day7 (’:i
....
i~)
Waningu~Qous
.....
O
" ’ ,,.. Gibbous
OF THE MOON
First
..... ,t. .;o,1,
B
I
nexl time you look
Phases of the Moon
As the moonIravels countcrclt)ckwisc ztrotmd lhc Earth (from above), and lhe
Earth-Moon system lravcls cotmlerclockwisc around Ihc Sun (from above),
Earthlin-s~. arc Ircatcd to zl lighting l)hcnomcntmknownas moonphases, h lakes
nearly 28 days for the moonto completely circle the Earth. As the lllOOla travels
around Ihc Earth, one side of the moonis always lit unless the earth is blocking
tl~e sun’s light, which we call a lunar eclipse. If you look at the Earlh-Moonsystem from afar, you would scc Ihe Earth and Moon lit up the same.
PHASES
-
Crescen.:..
moon is bcsl viewed through a Iclescopc not when it is full, but rather when it is
in any oue of its partial phases. This is when you get the most [iclp [roll~ the sun,
and can scc the terminalor
~
~
,.
Day21
~...
Waxing Crescent
Sunlight
’ "I,I~ ~w ~OOn
:..
~
...t...,Waning
.......
Cres~n:
Sunlight
Last Qua~er
Courtesy
of: "1001Things
Everyone
Should
Know
AbouttheUniverse",
byWdllam
A. Gutsch.
Jr. Ph.D.,DoubleDay
Dell, New
York
SOUTH
The changing phase of thc mnon as it inures acrnss the sk). The sequence of images is at oneday intervals just after sunset. Whenthe moonis in the direction uf the sun, tin the west) the
sun lights up the far side of the moonand the dark side faces us. The dark side may be harely visihle due In "earlhshine’: sunlight reflecting nff the Earth illuminating the Mnnn. Each
day a little mnreof the illuminated side becmnesvisible aroundIhe edge of the moonfacing the
sun. The illuminated portion appears first as a crescent, then a half disk, then gibbnus, and
finally a frill disk wheuthe mounis at opposition R~pposite the sun in the sky, rising at sunset,
overhead at midnight).
9