@

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. ñ 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: I. Earth is 1 CM. in diameter (Moon is 3 MM. (1/8 IN.) and 30 CM. away) Sun is 110 CM. (3 « FT.) in diameter and 110 M. or 360 ft. away 1 L.Y. is 5000 miles Nearest star 20,000 miles II. 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 200 miles away Galaxy is 5,000,000 miles across III. 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 1/2ø 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. STAR L.Y. Alpha Centauri 4.3 Sirius 8.7 Procyon 11 Altair 17 Fomalhaut 23 Vega 27 Pollus 35 Arcturus 38 Capella 46 Castor 47 Aldebaran 64 Regulus 78 Alpha Ursae Majoris 105 (Pointer in Big Dipper) Most of the stars in Orion are 500-600 L.Y. away. What's in a Name on the Planets? Planetary geographical features have Latin names. The following are in use, with the literal Latin translation in parentheses. Followed by the geographical meaning. Catena (Chain) Chain of small craters Cavus (Hollow) Steep-walled pit Choas (Choas) Extremely irregular terrain Chasma (Gorge, Chasm) Long, deep valley or rift Dorsum (Spine) Ridge Fossa (Trench) Shallow fissure Labyrinthus (Maze) Complex network of channels Lacus (Lake) Small lava plain. Used only on Moon Lines (Line) Line or band Macula (Spot) Dark spot Mare (Sea) Large lava plain. Used only on Moon Mensa (Table) Flat-topped hill, mesa, table-land Mons (Mountain) Mountain, pl. Montes Oceanus (Ocean) Large lava plain. Used only on Moon Palus (Swamp) Small lava plain. Used only on Moon Patera (Saucer) Volcanic crater or caldera Planitia (Plain) Low plain, basin Planum (Plain) Plateau Regio (Region) Region Rima (Crack) Small fissure Rupes (Cliff) Cliff or scarp Scopulus (Crag, Ledge) Irregular scarp Sinus (Bay) Embayment. Used on Moon, Mars Sulcus (Furrow) Network of ridges Terra (Land) Continent-sized land mass Tholus (Dome) Dome, usually volcanic Vallis (Valley) Valley Vastitas (Wasteland) Large plain Adjectives: Australis, Meridionalis - South Borealis, Septentrionalis - North 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 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 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. WHAT'S INSIDE A PLANET? True Path Predicted Path MASS: Found from gravitational effects on paths of other planets or spacecraft. VOLUME: Calculated from size: V = ãd3 6 BULK DENSITY = MASS/VOLUME DENSITY Grams/cu.cm. Less than 1 1 1-2 2.5-3.5 More than 3.5 PROBABLE MATERIAL Dense gases ice ice mixed with rock rock rock with dense core EXAMPLE Saturn Europa, Iapetus Ganymede, Titan Moon, Mars Earth, Venus, Mercury

Return to Outline Index

Return to Professor Dutch's Home Page

Created 27 Dec 1996

Last Update 20 May 1997

Not an official UW Green Bay site