Scale of the Solar System and Universe

Steven Dutch, Professor Emeritus, 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 ourgalaxy 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 denselythan 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

19831980BicentennialWatergate1970Landing on moonSix-day WarWatts RiotsJFK Shot1960First SatellitesKorean War1950World War II1940Depression19301920World War I1910First Airplane 190018901880Custer's Last Stand1870Civil War18601850California Gold Rush1840Yr.=31.4 million sec. 

Geologic Time = 1 Year

Birth of Christ - 11:59:46 on Dec. 31 pmChristmasThanksgivingNov.Oct.Sept.Aug.Jul.JuneMayApr.Mar.Feb.Jan.1 sec = 143 years1 day = 12,300 yr. 

GEOLOGIC COLUMNNOW-100 M.Y.First Birds-200First Mammals-300 First ReptilesFirst Amphibians-400First Fish-500-600 Start of the Cambrian First good fossils-1000Keeweenaw Volcanic Rocks-2000-3000 Earliest LifeOldest Known Rocks-40004500 Earth Formed 

---

Return to Planetary Images Index
Access Course Notes on Planetary Geology
Access Astronomy Notes Index
Return to Professor Dutch's Home Page

Created 27 Dec 1996, Last Update 11 January 2020