Scale of the Solar System and Universe

Steven Dutch, Natural and Applied Sciences, University of Wisconsin - Green Bay

SIZE OF THE UNIVERSE

DIAMETER EARTH 8000 MI.
SUN 860,000 MI.
EARTH-SUN DISTANCE 93,000,000 MI.
DISTANCE TO PLUTO 4,000,000,000 MI.
ONE LIGHT-YEAR 6,000,000,000,000 MI.
NEAREST STAR 4 L.Y. = 24,000,000,000,000 MI
DIAMETER OF THE GALAXY 100,000 L.Y. = ABOUT 1,000,000,000,000,000,000 MI.
DISTANCE TO THE ANDROMEDA GALAXY 3,000,000 L.Y. ABOUT 20,000,000,000,000,000,000 MI.

These numbers are so large as to be meaningless, so let's build some scale models:

Earth is 1 cm. in diameter

Moon is 3 mm (1/8 IN.) and 30 cm away)
Sun is 110 cm (3.6 FT.) in diameter and 110 M. or 360 ft. away
1 L.Y. is 5000 miles
Nearest star 22,000 miles

Earth is a grain of sand 1/100 cm in diameter

Sun is 1 cm in diameter and about 1 m. (3 ft.) away
1 L.Y. is 50 miles
Nearest star is 220 miles away
Galaxy is 5,000,000 miles across

The Sun is a grain of sand 1/100 cm in diameter

Earth is .0001 cm (size of a bacteria)
Earth is 1 cm from the Sun
Pluto is 40 cm from the Sun
Nearest star is two miles away
We estimate there are 100,000,000,000 stars in our galaxy. On this scale, all the stars in our galaxy are represented by 4 cubic feet of sand.
The galaxy is still 50,000 miles across on this scale.
If equally distributed: an area the size of Wisconsin would have about 700,000 sand grains.
One square mile would contain 13 sand grains.
Two sand grains at opposite ends of Lambeau Field would fill the stadium with sand more densely than space is filled with stars.
The Andromeda Galaxy is 1,500,000 miles away.

The Sun and Moon span angles of 1/2 degree in the sky - much smaller than a dime held at arm's length. The Sun is a typical star. The nearest star, Alpha Centauri, is much like the Sun. It would appear the size of a sand grain seen two miles away (an angle of 1/100 sec of arc). Chances are, you can see a star whose light started on its way here when you were born, if its distance in light years equals your age.

D-LY	Proper Name	Catalog Name	V mag
4.4	Rigel Kent	alpha Centauri	-0.01
8.6	Sirius	alpha Canis Majoris	-1.44
11.4	Procyon	alpha Canis Minoris	0.4
16.8	Altair	alpha Aquilae	0.76
19.4		eta Cassiopeae	3.46
24.4		beta Hydri	2.82
25.1	Fomalhaut	alpha Piscis Austrinus	1.17
25.3	Vega	alpha Lyrae	0.03
33.7	Pollux	beta Geminorum	1.16
35.2		zeta Herculis	2.81
36.2	Denebola	beta Leonis	2.14
36.7	Arcturus	alpha Bootis	-0.05
37.0		eta Bootis	2.68
38.5		delta Capricornis	2.85
38.6		gamma Virginis	2.74
40.1		beta Trianguli Australis	2.83
42.2	Capella	alpha Aurigae	0.08
46.7	Rasalhague	alpha Ophiuchi	2.08
48.8	Alderamin	alpha Cephei	2.45
51.5	Castor	alpha Geminorum	1.58
54.4	Caph	beta Cassiopeae	2.28
57.7		delta Leonis	2.56
58.6		iota Centauri	2.75
59.6		beta Arietis	2.64
60.9		theta Centauri	2.06
62.7		rho Puppis	2.83
65.1	Aldebaran	alpha Tauri	0.87
65.4		epsilon Scorpii	2.29
65.9	Hamal	alpha Arietis	2.01
71.3		alpha Hydri	2.86
72.0		epsilon Cygni	2.48
73.2	Unukalhai	alpha Serpentis	2.63
74.7	Alphekka	alpha Coronae Borealis	2.22
77.2		alpha1 Librae	2.75
77.3		lambda Sagitarii	2.82
77.4	Ankaa	alpha Phenicis	2.4
77.5	Regulus	alpha Leonis	1.36
78.1	Mizar	zeta Ursae Majoris	2.23
79.4	Merak	beta Ursae Majoris	2.34
79.7		delta Velorum	1.93
80.9	Alioth	epsilon Ursae Majoris	1.76
82.0		beta Ophiuchi	2.76
82.1		beta Aurigae	1.9
83.6	Phad	gamma Ursae Majoris	2.41
84.1		eta Ophiuchi	2.43
87.7		eta Draconis	2.73
87.9		gamma Crucis	1.59
88.8		beta Eridani	2.78
89.0		zeta Sagitarii	2.6
92.8	Algol	beta Persei	2.09
95.8	Diphda	beta Ceti	2.04
97.0	Alpheratz	delta Pegasi	2.07
99.4		delta Cassiopeae	2.66
100.6	Alkaid	eta Ursae Majoris	1.85

Most of the stars in Orion are 500-600 L.Y. away.

GEOLOGIC TIME

1 SECOND=1 YEAR 1983 1980 Bicentennial Watergate 1970 Landing on moon Six-day War Watts Riots JFK Shot 1960 First Satellites Korean War 1950 World War II 1940 Depression 1930 1920 World War I 1910 First Airplane 1900 1890 1880 Custer's Last Stand 1870 Civil War 1860 1850 California Gold Rush 1840 Yr.=31.4 million sec.

GEOLOGIC TIME = 1 YEAR Birth of Christ - 11:59:46 on Dec. 31 pm Christmas Thanksgiving Nov. Oct. Sept. Aug. Jul. June May Apr. Mar. Feb. Jan. 1 sec = 143 years 1 day = 12,300 yr.

GEOLOGIC COLUMN NOW -100 M.Y. First Birds -200 First Mammals -300 First Reptiles First Amphibians -400 First Fish -500 -600 Start of the Cambrian First good fossils -1000 Keeweenaw Volcanic Rocks -2000 -3000 Earliest Life Oldest Known Rocks -4000 4500 Earth Formed

Return to Outline Index

Return to Professor Dutch's Home Page

Created 27 Dec 1996

Last Update 04 September 2003

Not an official UW Green Bay site