ASTRONOMY - Jim Colyer

I have had 3 rounds of astronomy. Round 1 was as a teenager in the early 1960s. I learned the constellations and watched meteor showers. Round 2 was in my 30s in the early 1980s. At that time, I got into cosmology, learned the features of the moon and wrote my first astronomy paper. Round 3 was in my 50s. I subscribed to Astronomy Magazine, wrote my second paper and went to an Australian Star Party to see the stars of the Southern Hemisphere. Hopefully, I have achieved a permanence in the age of the Internet since astronomy is something I enjoy. History Each period in history sees the sky in a different way. The way a civilization perceives the sky is related to its travel capabilities. As man's sense of geography has increased so has his knowledge of the earth's place in the larger scheme. The Greek astronomer Ptolemy lived in the second century. He wrote a book called The Almagest. He put the earth at the center with the sun and planets going around it. This twisted view held sway for 1400 years. In 1453, Copernicus in Poland got it right. His book, De Revolutionibus Orbium Coelestium, expounded a heliocentric doctrine. Modern science was born. Really, Copernicus revived a long-forgotten idea of the Greek, Aristarchus. The Greeks had science. The Scientific Revolution grew out of The Renaissance which was a return to Greek ideas. The Middle Ages were dominated by the Church, and The Bible frowned on science. It put revelation above observation. Galileo clashed with the Church when he taught the earth goes around the sun. The road leading away from superstition and false information was a long one. For centuries, man's concepts of reality were shaped by The Bible. Nowhere in The Bible does it state that the earth is flat, but the implications are there: Satan taking Jesus to the mountaintop to show him the world's kingdoms, for example, and references to the "four corners of the earth." Heaven was above. Hell was below. Even Shakespeare retarded the growth of science by fueling legends of ghosts, witches and fairies. No wonder the people who first settled in America knew so little of the real nature of the Cosmos. Things were changing. Europe was expanding, and the printing press was spreading new ideas. By the time Columbus made his voyages, most people knew the earth was round. It became irrefutable when Magellan sailed around it, a gruelling three-year voyage during which Magellan was killed. Tycho Brahe was an observer. He found a supernova in Cassiopeia in 1572. As a theorist, he was a dud. He believed the planets circled the sun but thought that both planets and sun circled the earth. Even geniuses are wrong. He built his observatory close to Hamlet's castle in Denmark. He wore a nose piece because his nose had been partially cut off in a duel. It took Johannes Kepler, Tycho's assistant, to make sense of his work. Kepler's laws of planetary motion showed planetary orbits to be ellipses. They showed the closer a planet is to the sun, the faster it moves. William Herschel was the father of stellar astronomy. He built big telescopes and made the first model of The Milky Way. Erroneously, he placed our solar system at its center. His sister Caroline was an astronomer. Isaac Newton and Albert Einstein were physicists but laid the groundwork on which modern astronomy is built. Newton gave us the concept of gravity, the tendency of two bodies to attract whether they are the earth and an apple or the earth and the moon. Einstein introduced the theory of relativity. Relativity said time is relative to speed, that the speed of light is the only absolute. While the most distant galaxies are receding at 95% of the speed of light, they will never equal it. Gravity, Einstein said, results from space being curved. Newton, for all his brilliance, was an alchemist. Einstein did not believe the universe was expanding. Flawed genius! There is some question now about the speed of light being absolute. Why would it have to be? If we travelled faster than light, would we be in the dark when we reached our destination? Astronomy is best studied as a series of levels proceeding outward. Space has depth. There are motions within motions. Perspective rules. We explore the solar system. We reach for the stars. The Milky Way is but one of countless galaxies. We question the origin and fate of the universe. We search for extraterrestrial life. The Solar System The solar system began with a cloud of dust and gas. The cloud began to contract and spin. It contracted into a disc with the sun at the center. Planets formed from the disk. Gravity caused rocky, terrestrial planets to form near the sun. Gas giants floated further out. Every star in the galaxy may have a solar system. I wondered why all celestrial bodies are round. They are round because they are molded by gravity and the effects of spinning. The sun is a star. It is average in size. It is 93 million miles away. The sun's surface is 11,000 degrees. Sunspots are dark because they are cooler. The sun is a hydrogen bomb, shining by nuclear fusion. Hydrogen turning into helium emits energy in the form of light and heat. This energy is stored in fossil fuels: coal, oil and gas. Sunlight takes 8 minutes to reach us. The sun is a middle-aged star and will burn another 5 billion years. It will become a red giant. Earth's oceans will boil away. Its atmosphere will go. The sky will become black. The planets will be consumed. There are two kinds of objects, those that shine by their own light like the sun and those that reflect light like planets and moons. The planet Mercury is so close to the sun that many astronomers have never seen it. Pictures taken by Mariner 10 revealed Mercury's surface to be cratered like the moon's. Like the moon, Mercury has no atmosphere. NASA has launched the Messenger spacecraft to Mercury. Scientists want to know why Mercury is so dense. Like Mercury, Venus lies between Earth and the sun. For that reason, Venus never strays far from the sun in the morning or evening skies. It can be seen in the western sky after sunset. Venus goes through phases which are seen through a small telescope. Venus is brighter in its crescent phase because it is closer to Earth at that point. It gets as bright as -4.5 magnitude. Only the sun and moon are brighter. Venus is about the size of Earth. We might expect similarities. In fact, the surface temperature of Venus is 900 degrees because of the greenhouse effect. Its atmoshere consists of carbon dioxide. It is an inferno. Still, Venus accompanied by a crescent moon is one of the most beautiful sights in nature. Earth From space, Earth is a blue planet spotted with cloud tops. The earth is 25,000 miles in circumference and 8,000 miles in diameter. It revolves around the sun every 365 days, the period defined as a year. Earth's orbit varies over million of years. It stretches and shrinks over millions of years. This accounts for the 7 ice ages in Earth's history. The earth tilts on its axis by 23 1/2 degrees. This tilt causes seasons. The northern and southern hemispheres alternately lean toward and away from the sun. When it is summer in the United States, it is winter in Australia. Earth's moderate distance from the sun, not too near, not too far, is a factor in the evolution of life. It is neither too hot nor too cold. Liquid water can exist. Where there is water, there is life. It rained millions of years to create the oceans. Mountains were created by stresses in the earth. The earth's atmosphere came from volcanos. The atmosphere provides pressure and protection from ultraviolet rays. The oxygen in the atmosphere is produced by the photosynthesis of plants. Earth's atmosphere reaches out 300 miles. Life began in the sea (or so we have read). Four billion years ago, certain chemicals began showing characteristics of life. Viruses are on the boundery between the living and nonliving. One-celled organisms developed, microbes. Plants colonized the land. Invertebrates evolved. Vertebrates followed. Fish evolved into amphibians which evolved into reptiles. Dinosaurs lived in the Mesozoic Era between 65 million and 220 million years ago: Tyrannosaurus, Brontosaurus, Triceratops, Stegosaurus, Duckbills, Ankylosaurus. My paper, "The Other Sciences" was dinosaur-centered. A species is a group of animals whose members interbreed. There are over one million species of animals. The continents formed one land mass. As continental drift occurred, reptiles evolved into mammals and birds. Many paleontologists believe birds are dinosaurs. There was a golden age of giant mammals in the Cenozoic Era, mammoths and mastadons. Man has existed in some form for 5 million years. Man evolved from primates in southeast Africa and spread into Europe and Asia. From Asia, he populated the South Sea Islands and walked across the land bridge at the Bering Strait during the last Ice Age and down into the Americas. That was 50,000 years ago. The races as we know them came into existence at the end of the Ice Age 20,000 years ago. Civilization was born in Egypt and Mesopotamia. Recorded history spans 5,000 years. The colonization of the Americas by Europeans from the Renaissance onward is the most important human migration in history. World population is currently 6 billion. 300 million are in The United States. Natural history is understood in terms of the Geological Time Scale. Paleontologists study the fossil record. Fossils are found in sedimentary rocks, those laid down by water. Radio carbon dating determines the age of rocks. To know the age of a rock is to know the age of the fossil inside it. Environment I wrote "Save The Planet" because I am a songwriter. Now, I am faced with defending the message of my song. I am not a fanatic. I recall Al Gore's book about the environment. It was so technical, it was unreadable. It was funny when George Bush 41 referred to Gore as "Ozone Man" because of his preoccupation with the ozone layer. I have heard the ozone layer repairs itself. Maybe, maybe not. The big issue with Gore was global warming. This is the tendency for man-made carbon dioxide and other gases to trap heat in the earth's atmosphere. The fear is, the earth will be heated to a point that its polar caps melt, inundating coastal cities. Unchecked, Earth could become an inferno like Venus although we would be dead long before. The problem I have is that geologists say we are between Ice Ages. If another Ice Age is inevitable, might not global warming serve as a device for heating the globe? Carbon dioxide in the atmosphere could trap the sun's energy and prevent glaciers from flowing north and south to drive the earth's population toward the equator. This sounds crazy. We are trying to figure out whether we will burn up or freeze to death, if we are going to drown or die of thirst because all the water is locked up in ice. If global warming is taking place (and apparently it is), I am not sure that it is an entirely bad thing. It got pretty cold in Nashville last winter. If it is a bad thing, I am not sure that man in his ingenuity will not find a remedy. I stay mainstream. With the population of the earth at 6 billion and climbing, there is no doubt we have to manage natural resources more responsibly. The rainforest of South America can not be destroyed without consequences. We should be planting trees in North America, one for each one we cut down. Houses have traditionally been built from lumber. Books have been made from paper. All that can change. New building materials can be developed. Libraries will become electronic. The large mammals of Africa need to be protected otherwise they will become extinct in a few decades. This is largely up to the governments of African countries and their National Park systems. At the same time, it is a world problem. Man is one species despite his constant fragmenting into religious sects and nationalities. If man were to act as one species (and I am not promoting a one-race concept) and stop warring, he could put his house in order. The energy and money spent by Muslims, Christians and Jews fighting each other would go a long way toward utilizing alternative fuels. Fossil fuels will eventually be used up. It will take time (and no one knows how much), but the amount of coal, oil and gas in the ground is finite. If man does not prepare for the time when they are depleted, civilization will collapse. There is a lot of talk about alternative fuels and hybid cars. I am unsure how much research is being done and about the state of practical applications. People talk about running cars on vegetable oil. Gasoline is up to $2.50 a gallon. How much is a gallon of vegetable oil? The Moon In November, 1981, I used maps to identify the moon's most prominent features. The most obvious are the dark maria (seas). They are lava plains. Lava flowed from the moon's interior when impacts were hard enough. 5 maria combine to form a foot with 3 toes: the Sea of Serenity, Sea of Tranquillity, Sea of Crises, Sea of Fertility and Sea of Nectar. The moon is geologically dead. If a meteor hits, the resulting crater is more or less permanent. There are some interesting craters. Copernicus, Kepler and Aristarchus form a Y shape. Tycho in the south stands out. The southern highlands are riddled with pockmarks. Ptolomaeus is a big one. Aristarchus is the brightest spot on the moon. Plato is the darkest. Near Plato is a formation I call "The hips." Craters have central peaks. The peaks are caused by the ground bouncing back. The most recent craters have rays extending from them. The rays are material that was thrown out. The moon has mountain ranges. The Apennine mountains rise to 20,000 feet. Until recently, it was thought that the earth and moon formed at the same time. It now appears that the moon came into existence when a large asteroid crashed into the earth and ripped part of it away. This accounts for the moon having no metal core. Older theories are earth-based. Newer theories are space-based. Over time, the earth has slowed the moon's spin until it keeps the same side to the earth. The moon experiences 2 weeks of daylight followed by 2 weeks of night. There is no such thing as the "dark side" of the moon because the side we never see gets 2 weeks of daylight each month. From the moon, the earth is stationary but goes through phases. The sky on the moon is black because there is no atmosphere. Our blue sky is the result of light being reflected by air. Earthshine is seen during the moon's crescent phases when the moon is nearly in line with the sun and the earth, evening or morning. Earhtshine is sunlight bouncing off the earth, hitting the moon and coming back to our eyes. It is earth lighting up the lunar night. It can be noticed that the horns of the moon point away from the sun. The phases of the moon are new moon, crescent, first quarter, gibbous, full moon, gibbous, last quarter and crescent. The new moon is "no moon" because the side relecting the sun is turned away from us. The moon appears to wax and wane in its monthly orbit. Light travels between the earth and moon in 1.2 seconds. The line between day and night on the moon is called the terminator. The moon is about 240,000 miles from Earth, at our doorstep. If we drove around the world 10 times, we could be on the moon. The moon causes the tides in our oceans. It tugs at our atmosphere as well, but we are so deep in the atmosphere that we are unaware of it. The moon is imperceptively moving away from us. In March, 1960, I saw a total lunar eclipse. The full moon took on a dark, copper color but remained visible because sunlight was refracted onto it by the earth's atmosphere. An eclipse of the moon occurs when the moon passes through the earth's shadow. A lunar eclipse always occurs during a full moon. Usually, the moon passes above or below the earth's shadow. I saw a solar eclipse in Nashville in 1979. During a solar eclipse, the moon passes between the sun and the earth. The moon's shadow is small, so one has to be at a fairly restricted locale to see a solar eclpise. During an annular (ring) eclipse, a ring of sunlight circles the moon because the moon is at its maximum distance from the earth. It is a coincidence that the sun and moon appear to be the same size in the sky. American astronauts went to the moon 6 times between 1969 and 1972. 12 men walked on its surface. Neil Armstrong was the first. Armstrong made a mistake when he delivered his prepared statement. He said, "One small step for man, one giant leap for mankind." He meant to say, "One small step for a man." Apollo 11 landed in the Sea of Tranquillity. Eugene Cernan was the last man on the moon. The temperature of the moon's surface varies 500 degrees, from 225 degrees to -275 degrees. There is no sound on the moon because sound is the vibration of air. There is no color except for the blue earth in the sky. The moon's rocks showed the moon's minerals to vary somewhat from those found on Earth. There were no fossils in the moon rocks. Life began in the sea, and at no time past or present has the moon had water. The Russians took the first photos of the far side of the moon. There are not as many lava plains on the far side. A blue moon is the second full moon occurring in any month. Blue moons are not that rare. They occur every 2.72 years on an average. Wierdos are claiming man did not go to the moon, that it was staged. They offer as proof the American flag blowing in the wind in the picture supposedly taken on the moon. There is no wind on the moon. Fact is, NASA did something to the flag to make it stiff so it would stick out and could be seen. I do not know if people who think we never went to the moon are crazy or stupid or making a joke. I sat in a parking lot in Nashville a few years ago and debated a man named Bart Sibrel about this. Bart was convinced man never went to the moon. It came out in the national news that he approached Buzz Aldrin (the second man on the moon) in California and tried to force him to swear on a Bible that the moon landings were real. Buzz Aldrin punched Bart in the nose. Bart tried to sue. The Los Angeles County District Attorney's office refused to file a battery charge. Rest assured, man set foot on the moon and is on his way to Mars. The Outer Planets The outer planets exhibit retrograde motion. They appear to travel backwards against the stars as the faster earth overtakes and passes them. Mars is the most dramatic example. Percival Lowell is associated with Mars. From his observatory in Flagstaff, Arizona, he saw what he mistook as canals built by Martians. Mars gets its red color from dust storms that whip around it. Mars' surface contains rust (iron oxide). Its polar caps are made of dry ice (frozen carbon dioxide). There is a giant volcano known as Olympus Mons and a canyon called Valles Marineris. Mars' atmosphere is too thin for liquid water, but there is evidence that water once flowed. If it did, life may have evolved. The only way to know is to go there and bring back rocks to see if they contain fossils. A journey to Mars will take a year, 6 months to get there and 6 months to get back. The Viking spacecraft landed on Mars in 1976. It found chemicals said to mimic life. The 3 essentials for life are water, nutrients and energy. Scientists are studying Chile's Atacama Desert, the driest place on earth to try to learn about Mars. There is almost no rain in the Atacama and no life. The Mars Science Laboratory will be launched in 2009 and land on Mars in 2010. Its purpose will be to determine whether microbes evolved on Mars. There may have been a "zone of life" in the early solar system extending from Venus to the asteroids. The two Martian moons are Phobos and Deimos. In Homer's Iliad, they were Fear and Panic and attended the god of war. The asteroid belt lies between Mars and Jupiter. Jupiter's influence kept this collection of rocks from coalescing into a planet. Ceres and Vesta are large asteroids. Large worlds have atmospheres. Small worlds do not. A difference in size means a difference in gravity. Earth and Venus can hold atmospheres. Mercury and the moon can not. Mars, which is medium-sized, has a thin atmosphere. Worlds with atmospheres are not heavily cratered. Atmospheres vaporize meteors before they hit and erode craters caused by impacts. That is why the moon and Mercury are heavily cratered, Venus and Mars have some and Earth has just a few. Gas Giants Voyager 1 flew by Jupiter and Saturn and was deflected. Voyager 2 went on to Uranus and Neptune. Voyager 2 spent 12 years (1977-89) on its Grand Tour. All the gas giants were found to have rings. Jupiter is called a failed star. If it had been a bit larger, nuclear reactions would have begun and it would shine by its own light. It is made of hydrogen and helium, the most common elements. Jupiter has bands because it rotates so fast, its clouds get pulled into patterns. The Great Red Spot is a gigantic storm. The Galileo probe reached Jupiter in 1995. Jupiter has 60 moons. The 4 largest are Io, Europa, Ganymede and Callisto, named for Jupiter's lovers. They were first seen by Galileo who invented the telescope in 1610. Io is the most interesting. It has the only volcanos in in the solar system beyond Earth. Saturn is a butterscotch ball of gas flattened at its poles. It is light enough to float in water. Saturn's rings are its glory. The rings are made of rock and ice. There are 7 main rings. As Saturn orbits the sun every 29-years, we see the rings open at the top, edge-on, open at the bottom and edge-on again. Saturn has 31 moons. Titan is larger than Mercury. Titan is the only moon in the solar system with an atmosphere. Its atmosphere is orange and very dense. Cassini was Italian-French. He discovered the major gap in Saturn's rings. Huygens, a Dutch astronomer, discovered Titan. The Cassini-Huygens spacecraft is the first to orbit Saturn. In early 2005, the Huygens probe descended into Titan's atmosphere. It sent back data. The reason for studying Titan's atmosphere is that it is thought to be similar to Earth's early atmosphere. Scientists want to learn how life developed. $3.3 billion was spent on Cassini. I wish they had given me a million and cut some corners. It is strange, the money spent and the hype surrounding these projects and how so little comes from them. Uranus was knocked on its side. Modern astronomy is explained in terms of collisions. Consider the theory that dinosaurs were killed by an asteroid. If the ancients thought the heavens benign, today's universe is a place of violence. Uranus is as featureless as a green pool ball. It was discovered by William Herschel in 1781. Voyager 2 photographed Neptune's Great Dark Spot midst blue methane. The small, rocky Pluto at the edge of the solar system breaks the rules. Its orbit is erratic, bringing it inside Neptune. Pluto may have been a moon dislodged from somewhere else or part of the Kuiper Belt. It has a companion, Charon. Clyde Tombaugh discovered Pluto in 1930. NASA launched the New Horizons spacecraft in January, 2006. It will take nearly 10 years to reach Pluto at a distance of 3 billion miles. Pictures will be sent back in the summer of 2015. I will be almost 70 and plan on being here to see them. The Voyagers have left the solar system and are on their way to the stars. They contain records of earth sounds, music and languages. Comets and Meteors The solar system and everything in it is 4.6 billion years old. This includes the sun, the planets and their moons, comets and meteors. Comets are scraps left over from the formation of the solar system. In that early period, there was a lot of debris. Craterization took place on a massive scale. Comets have been called "dirty snowballs." They circle the sun. Comets develop tails as the sun melts ammonia and methane ice. The tails extend for millions of miles and point away from the sun, driven out by the solar wind. Halley's comet goes out beyond Neptune, returning every 75 years. Halley was not the first to see the comet but the first to predict its return. I saw comet Ikeya-Seki on Halloween morning, 1965. It was dim and fuzzy but worthwhile. Kohoutek bombed as did Halley's. I saw Hyakutake in 1996 and Hale-Bopp in 1997. It took 30 years to see my second comet, which I spotted the morning of March 24, 1996. Comet Hyakutake was as bright as the Big Dipper stars and extended its handle. It was fuzzy but had no discernible tail. Two mornings later, it had moved by The Little Dipper. The morning of March 27, it was under the North Star. Hyakutake upstaged Hale-Bopp which had gotten the advanced publicity. The Japanese are comet hunters. Shoemaker-Levy 9's impact with Jupiter gave astronomers their first glimpse of a collision in space. Jupiter is like a vacuum cleaner, sucking up stuff and protecting Earth. In the early 1960s, I began watching The Perseids. The Perseids is the best meteor shower and occurs annually in August. The night of August 11 and morning of August 12, 1964, I counted 351 meteors. Toward morning, they were dropping out of the east like snowflakes. Many were bolides, leaving bright trails. The best one appeared after daybreak. Cousin Larry was yelling, and I looked up to see a meteor as large as a full moon. It was exploding and changing colors. Meteor showers are associated with comets. As comets orbit the sun, they leave behind trails of debris. Meteoroids get strung out along comet paths. Most of the stuff that enters our atmosphere to put on a show is no larger than sand. Most meteors are vaporized by friction about a hundred miles up. In any given shower, meteors emanate from a point in the sky called the radiant. Meteor showers are named after the constellations behind their radiants. We see more meteors toward morning because we are driving into them. The Perseids are associated with comet Swift-Tuttle. Meteors are called meteorites when they survive and fall to earth. Meteorites are composed of iron and nickel. Meteor Crater near Winslow, Arizona is evidence of a large meteorite that fell 50,000 years ago. Meteor Crater is privately owned. 200 impact craters have been found around the world. There is one near Odessa, Texas. Wolf Creek Crater is in Australia. Thousands of meteorites have been found on the ice in Antarctica. O. Richard Norton says meteorites are pieces of asteroids. The largest meteorite found in The United States was found in Willamette, Oregon. I saw it in The American Museum of Natural History in New York City. There is one instance of a person being hit by a meteorite. In 1954, a woman in Alabama was sleeping on her couch when a meteorite came crashing through the roof. It ricocheted and hit her in the side, inflicting a large bruise. Craters are being mapped from the Space Shuttles. Comets and asteroids create impact craters. The idea that dinosaurs were killed off by a large asteroid became popular in 1980. Scientists point to Chicxulub (Cheek-shoe-lube) crater in Mexico's Yucatan peninsula as being the impact that killed not only the dinosaurs but 2/3 of all species. That is pinning it down. The evolution of life on earth may be driven by impacts. Something hit Siberia in Russia in 1908. It is called the Tunguska Event. Trees were flattened but no crater was found. It was a comet or asteroid which vaporized before impact. The earth's atmosphere acts like sandpaper, constantly smoothing things out. Water erodes craters. Otherwise, the earth would look like the moon. Plate tectonics also reshape the earth. Stars The stars are always there, even in the daytime when they are blotted out by the sun. That is something we may not understand as children. As the earth revolves in its yearly orbit, different parts of the stellar panorama are exposed in the night sky. Constellations are identified with seasons. Constellations are two dimensional. They are illusions. They existed in the minds of the ancients who imagined them. Stars are three dimensional. They are at various distances. Some appear bright because they are close. Others appear dim because they are far away. The most easily identifiable constellations are the Big Dipper (Ursa Major), Orion, Scorpius and the Southern Cross. The pointers in the bowl of The Big Dipper point to Polaris, the North Star. Polaris is overhead at the north pole and retains its fixed position as the earth spins. It is a tiny bit off. This causes precession of the equinoxes and a shift away from Polaris as the North Star. Given enough time, 26,000 years, the earth wobbles like a top. The Zodiac consists of Aries, Taurus, Gemini, Cancer, Leo, Virgo, Libra, Scorpius, Sagittarius, Capricornus, Aquarius and Pisces. The sun, moon and planets remain against the background of the Zodiac because of the flatness of the solar system. It is all in the same plane. The flatness is caused by spinning. The most elaborate story in the sky is that of Perseus and Andromeda, told by a group of autumn constellations. There are Andromeda's parents, Cepheus and Cassiopeia, and the monster, Cetus. Pegasus is there, the winged horse ridden by Perseus. In Perseus' hand is the head of the evil Medusa as represented by Algol. The constellations are a product of Greek and Roman mythology. But even the Greeks borrowed from the Babylonians. Despite their relative distances, stars forming the constellations are in the vicinity of the sun when we picture the entire Milky Way. The Greeks saw the Milky Way in poetic fashion. Legend had it that Hercules was born after an affair between Zeus and a mortal. When Zeus tried to get his wife, Hera, to suckle the baby, she pushed it away and her milk flowed across the sky. Visible stars range from 1st to 6th magnitude. The brightest stars are Sirius, Canopus, Alpha Centauri, Arcturus, Vega and Capella. The Arabs named them. Stars twinkle because of our atmosphere. We see 4000 at any one time. Stars are so far away that they appear only as points of light in the largest telescopes. The stars are trillions of miles away. Their distances are measured in light-years. A light-year is the distance light travels in a year, 6 1/2 trillion miles. Light is the fastest thing in the universe (Does it have to be?) at 186,000 miles per second. The closest star is Proxima Centauri, a companion to Alpha Centauri, 4 light-years or 25 trillion miles away. Double stars are the rule rather than the exception. Algol is a double star. So is Mizar, the second star in the handle of The Big Dipper. Another double is Albireo at the end of Cygnus the Swan. The contrast between the blue star and its yellow companion is striking. Castor in Gemini is a system of 6 stars. Stars are like people. They are born. They age. They die. Stars are born when gaseous nebulae shrink under their own gravity. Mass determines whether a celestial body will be a star. If the mass is great enough, the pressure and temperature at the core will be great enough for nuclear reactions to begin. Stars form in clusters. The Pleiades are stars condensing from surrounding gas. The Orion Nebula is a stellar nursery. The Trifid Nebula is a nursery. Nebulae glow because they reflect starlight. The Horsehead Nebula is a dark nebula outlined by starlight behind it. Stars come in colors. Blue-white stars are the youngest and hottest. They are in the spiral arms of The Milky Way. Red giants are the oldest and coolest. Yellow stars like our sun are in the mid-temperature range. The oldest stars are in globular clusters surrounding the hub of The Milky Way. Walter Baade studied star populations. Stars die in two ways. Average stars like our sun become red giants. They die peacefully by exhausting their fuel. Antares and Betelgeuse are red giants. When a star uses its hydrogen it starts burning helium to make carbon. Elements are created in the cores of stars. Our bodies are made from remnants of ancient stars. A dying star becomes a planetary nebula when it gives off a shell of gas. The Ring Nebula in Lyra is a planetary nebula. "Planetary nebula" is a bad name as it has nothing to do with planets. A dying star shrinks to become a white dwarf. A white dwarf is the core of a red giant. White dwarfs can be red or brown but are still called white dwarfs. A massive star dies by becoming a supernova and blowing itself up. A supernova was seen in the Large Magellanic Cloud in 1987. Supernovae become pulsars. A pulsar can become a black hole. A black hole is a collapsed star whose gravity is so great that even light can not escape it. Black holes are at the centers of some galaxies. Cygnus X-1 is a black hole. A quasar is a galaxy falling into a black hole. The Milky Way The Milky Way is our own galaxy, and we are locked inside it. This is not apparent right away as we tend to think of it as merely a glimmering arch in the night sky. The ancients thought of spilt milk. But the Milky Way consists of 400 billion suns 100,000 light years across and 2,000 light-years thick. If we could stand outside the Milky Way we would see a disk with a bulge in its middle. It is shaped like a flying saucer. Our solar system revolves 2/3 of the way from the center toward the rim. It takes 200 million years for our solar system to revolve around our galaxy. This is called the cosmic year. The last time our sun and its planets were in this same position, dinosaurs ruled the earth. In the desert in 1979, there was an instant when I felt myself revolving around the galactic center. Since we are inside the galaxy, trying to divine its shape is analogous to a person inside a house trying to determine the shape of the house. The structure of the Milky Way and our sun's position in it was ascertained by Harlow Shapley in 1917. We can see it if we know what we are looking at. The Milky Way circles our sky. The bulging center of its disk lies in the direction of Sagittarius where the star clouds are thickest. The thinnist part of the circle, visible in winter, is in the direction of the outer rim. When we look at right angles to The Milky Way we are looking out the top or bottom of the disk where the stars are sparse. As might be expected, more galaxies can be seen out the top or bottom. Patches of dust like the Cygnus Rift and the Coalsack obscure parts of The Milky Way. People used to think they were holes. Because of dust, radio telescopes are used to study the center of the galaxy. The Milky Way is 10 billion years old. Cosmology The universe is 15 billion years old. 15 billion years ago, all the stuff in the universe was concentrated in a singularity, a mathematical concept for the primeval atom, a speck of infinite density. It exploded. This is what astronomers call The Big Bang, the point at which time began. The term was coined by George Gamow. Primordial energy and matter began flying in all directions. It cooled. Gas clouds condensed into galaxies. Galaxies are aggregates of stars. They are the building blocks of the universe. Estimates put the number of galaxies in the universe at 100 billion. Some are distinctive. The Sombrero and Whirlpool look like works of art. Some collide. Galaxies are categorized according to their structures: spiral, barred spiral, elliptical. The Milky Way is a spiral. The Magellanic Clouds of The Southern Hemisphere are irregular. They are satellites of The Milky Way. The Milky Way belongs to a Local Group of 31 galaxies. The Andromeda Galaxy, M31, is part of The Local Group. It is a spiral similar to The Milky Way but much larger. It is 2.3 million light-years from us and the only galaxy visible to the naked eye from The Northern Hemisphere. It is a faint, hazy patch. It is the fartherest visible object. Numbers were assigned to all fuzzy patches in the sky by Charles Messier, an 18th century comet hunter. He cataloged 103 objects so as not to mistake them for comets. Nebulae, globular clusters and galaxies were lumped together. The more thorough New General Catalog (NGC) dates from the 19th century. Galaxies are found in clusters, and these in turn comprise superclusters. The Virgo supercluster and the Coma Berenices supercluster are enormous. Our Local Group is part of the Virgo supercluster. In spite of all this, the universe is mostly empty. Proof of the Big Bang came from the work of Edwin Powell Hubble. By applying The Doppler Effect to light, Hubble found that light from galaxies showed a redshift. This suggests that galaxies are receding or travelling away from each other. This is what is meant by The Expanding Universe. If you run it backwards, there is a point at which all galaxies converge. The primeval atom! Furthermore, the farther apart the galaxies get, the faster they travel. This is known as Hubble's Law. The question becomes whether this expansion will continue forever or whether there is enough gravity in the universe to pull it back together. This would be the Big Crunch and suggests an oscillating universe, one that is alternately expanding and collapsing. Black holes may provide the gravity to cause a Big Crunch. The universe is not expanding in space. Space is being created as the universe expands. The balloon analogy is used, blowing up a balloon with dots on it to represent galaxies. We ask what there was before the Big Bang. The answer is nothing. There was no space, no time and no events. It was the beginning in the truest sense. Penzias and Wilson provided further proof of The Big Bang when they detected its background radiation. E.P. Hubble was the greatest astronomy of the 20th century. Shapley was great but believed that external galaxies were inside our own. Cosmology was the step I was trying to take since I was a teenager. Carl Sagan's Cosmos series in 1980 was a breakthrough. To paraphrase Sagan, "The Cosmos is everything that has been, everything that is and everything that will be." Sagan saw man as poised on the shore of the cosmic ocean, intelligent life as a means for the cosmos to know itself. The terms "cosmos" and "universe" are interchangible. Telescopes In "Swim With Dolphins," I wrote, "I wanna see the stars, Mauna Kea's calling me." September 13, 2003, I stood atop the extinct volcano, 13,750 feet above sea level. "This is beautiful!" I thought. The mountain was stark and brownish, barren of vegetation. There was a Mars-like surrealism. I watched the sun set above the clouds. I saw the stars. They blazed. The Milky Way, the plane of our galaxy, arched brilliantly overhead. I was on the Big Island of Hawaii in the middle of the Pacific Ocean. It gets no better than this. Hawaii is at 20 degrees northern latitude, so the north star appears lower in the sky and Scorpius higher than from Kentucky/Tennessee although nowhere near as high as from Australia where it gets straight up. I sensed the curvature of the earth. Mars was at its closest. I wondered why it was less red than when it was farther out. The increased sunlight on its surface neutralized its redness. The moon rose. I like astronomy and got to see a bit of everything. 13 telescopes spread across the summit of Mauna Kea. There are the Keck domes and the Japanese telescope called Subaru. Sabaru is Japanese for The Pleiades. The University of Hawaii and Caltech run Mauna Kea. It is the only large observatory I have seen. I was above 40% of our atmosphere's oxygen. It misted at the visitors center on the drive up. Rainbows were everywhere. I felt invigorated. Beauty heals. There are two kinds of telescopes. The refractor was invented by Galileo. The reflector was invented by Isaac Newton. The purpose of both is to collect light. The refractor does it with an object lens. The reflector does it with a mirror. The biggest telescopes are reflectors like those at Mount Palomar in California and Kitt Peak in Arizona. The invention of photography revolutionized astronomy. Photographic plates record more detail than the human eye. The pictures we see in books are long-exposure photographs. The CCD (charge-coupled device) is a camera replacing photographic plates. The Hubble Space Telescope was put into orbit by The Space Shuttle. Because it is above the atmosphere, its pictures are superior to those of earthbound telescopes. I was disappointed with the Space Telescope. It produced books full of chaotic pictures and no comprehensive breakthrough in knowledge or theory. The far side of the moon is the ideal spot for an observatory. Planetariums are places where sky shows and lectures are given. Star patterns are projected inside a dome. I have visited planetariums in Louisville, Nashville, Salt Lake City and New York City. Space Travel The Soviet Union kicked off the Space Age in 1957 with Sputnik. The following year, The United States established NASA (National Aeronautics & Space Agency) I remember standing in the yard and waiting for Echo I to fly over. Th original 7 Mercury astronauts were John Glenn, Gus Grissom, Alan Shepard, Wally Schirra, Deke Slayton, Gordon Cooper and Scott Carpenter. John Glenn got a hero's welcome in 1962 after orbiting the earth 3 times. Gus Grissom died with Roger Chaffee and Ed White in a fire during a test. Saturn 5 rockets sent men to the moon. Apollo 11 was the first moon landing. Neil Armstrong's footprints will last for millions of years. Buzz Aldrin was the second man on the moon as Michael Collins orbited above. Apollo 13 was brought back when an oxygen tank exploded. That was 1970. I was on my way to Germany. The 12 Apollo astronauts who walked on the moon are: Apollo 11 - Neil Armstrong, Buzz Aldrin Apollo 12 - Charles Conrad, Alan Bean Apollo 14 - Alan Shepard, Ed Mitchell Apollo 15 - Dave Scott, James Irwin Apollo 16 - John Young, Charles Duke Apollo 17 - Harrison Schmitt, Eugene Cernan The Apollo program has been followed by a golden age of planetary exploration. NASA has worked with the Jet Propulsion Laboratory of the California Institute of Technology. JPL launched Pioneers 10 & 11 and the Voyagers which are headed for deep space. Competition between The U.S. and The Soviet Union drove the Apollo program. The spirit of cooperation that is supposed to put men on Mars is proving less of a motivator. America's space program inches along. Challenger and Columbia blew up but the Space Shuttle Discovery flew again in July, 2005. Circling the globe in 90 minutes may not rival an expedition to Mars but it is not bad. The Shuttles orbit 200 miles up. The most famous people to fly in the Shuttles are women, Sally Ride and the ill-fated Christa McAuliffe. The International Space Station is up and running. Michael and I got a feeling for it at The Kennedy Space Center at Cape Canaveral. Shuttle missions fly to the ISS. 21 nations are involved. The Shuttles will be retired in 2010. Something called the Crew Exploration Vehicle (CEV) will be used to carry crews and supplies to the International Space Station. NASA has a plan to return to the moon by 2018, and the CEV will take 4 men to the moon for a 7 day stay. The CEV will be designed to carry 6 men on to Mars at some point. Futurists let their imaginations run wild. They foresee mining the moon, terraforming Mars and colonizing the galaxy. Congress is skeptical of SETI (Search for Extraterrestrial Intelligence) although interest remains. Estimates of the number of alien civilizations range from zero to a certainty that the universe is teeming with life. Astronomers began finding extrasolar planets in 1995. The first planet spotted in another solar system orbits 51 Pegasi. 160 extrasolar planets have been found. A system with 3 planets was found around a star in Andromeda. The extrasolar planets found so far have been gas giants like Jupiter, unlikely candidates for harboring life. A microlensing technique is used to search for Earth-ish planets. The idea that life began in the sea has come into question in the Space Age. It may be that Earth was seeded from another solar system within the Galaxy. The seeds of life may have travelled through interstellar space to take root in the favorable conditions of planet Earth. This is the theory of Panspermia. Spores are the hardiest form of life. They may travel between planets via comets and meteors. Spores are less likely to travel through interstellar space, but we can not rule out the possibility. Our perception is evolving as we reach into space. One thing seems sure, the UFO sightings that began after World War II, the close encounters and abduction stories are false. Such phenomena are explainable as aircraft or balloons, Jupiter or Venus, science fiction, psychiatric cases, hoaxes and lies. Roswell is a hoax. Suspicion that the government is concealing information about UFOs is absurd. Physics Energy is the ability to do work. There are 4 forces in nature: the gravitational field, the electromagnetic field and the strong and weak nuclear fields. Gravity is the weakest but is very long-range. Electromagnetism includes electric and magnetic fields. The strong nuclear field holds protons and neutrons together. Atomic and hydrogen bombs use its energy. The weak nuclear field is associated with radioactive decay. Wierd The more exotic ideas seem like they belong in a Star Wars movie. Something called Dark Matter is supposed to account for 90% of the mass in the universe. We can not see it nor can it be detected by our instruments. Is it really there? Wormholes are far out. They are tunnels in black holes that lead to parallel universes. Is there not one universe? The word itself means "one." If there have been other singularities and Big Bangs, they must be part of the one universe. Science versus Religion According to the Bible, the Virgin Mary got pregnant without Joseph's sperm or genetic material. An egg fertilized by Spirit? Can we believe this? An angel informed Mary's husband of her pregnancy. Can we believe angels really exist as Billy Graham does or regard them as relics of Hebrew mythology, fabrications of man's fertile brain? The star of Bethleham! Chances are it was a literary star with no counterpart in nature. Someone is always trying to prove it was a comet or planets lined up. So many things in The Bible are perceived as the fulfillment of prophecy. Should we take this stuff literally or view it as a body of legends that took shape in the collective mind of ancient Middle Eastern tribes. With prophecy, we work backwards. We invent prophecy after the fact. Is there such a thing as sin? Sin does not exist in nature. A cat kills a mouse. No sin. Billy Graham believes in demons. I am 59 years old and have never seen a demon or evidence of a demon. Nor have I seen a miracle. The Bible is a string of impossibilities. Some people say these things do not happen today but happened back then. The notion is ludicrous. Why do we bend over backwards trying to force reality into a theological frame? If Jesus is God, why not set things right for all time now? We are waiting. If the universe is 15 billion years old, will it take Him another 15 billion? Can we believe Jesus ascended into heaven? He floated into space? Have astronauts in the Space Shuttle orbited past Him? In film biographies of Jesus, he has those piercing blue eyes. The Anglo-Saxon Jesus! He reels off parables that sound like vague riddles to the modern world. The surest way to confuse is to use a parable, analogy, metaphor or simile. What is the Kingdom of God? What is God? Where is He and where did He come from? Is theology man's invention? Books, art and movies take things out of contxt. They distort reality into episodes with the hope of commercial success. Does the Bible do this? If not, why do we have to buy a Bible in a book store to read the word of God? Why do preachers preach until they are blue in the face and then ask for money? Is their bottom line money? Apart from imagination and art, how could Jesus have raised Lazarus from the dead? The supernatural does not exist in a natural universe. Faith can not make the impossible happen. Yet, Jesus said, "I am the Resurrection, and the Bible says all things are possible with God. Those who speak of an empty tomb as evidence of the Resurrection, are they not failing to distinguish between an actual tomb and a tomb of the mind? Preachers wear suits and ties and give the appearance of being sane, rational people. When they speak of a rapture and physically rising through the atmosphere to leave behind the unredeemed, we realize something is amiss. Evangelist Jimmy Swaggert extolled virtue while patronizing prostitutes. Morality is most plausible when it has a scientific foundation. It was not science that used nuclear energy for bombs. It was a clash between tax-funded military establishments which have traditionally embraced religion. If one gets paid to perpetuate ignorance, he will generally do it. Mormons are on the cutting edge of Christianity. They claim Jesus came to western America to save Indians. If intelligent life is discovered in another part of the galaxy, a sect will arise claiming Jesus appeared to redeem lost aliens. The age of theology lay between 3,000 B.C. and 600 A.D. The age of science began only 400 years ago. Carl Sagan, in his book, "The Demon-Haunted World," called science the candle in the dark. Science is the way, evolution over creationism, observation over revelation, objectivity over subjectivity. Our eyes and ears tell us the way things are. It is as we suspected when we were growing up, before organized religion sapped our energy. Religion is flawed thinking. We are physical, not spiritual. We are alive when we are alive. We are dead when we are dead. We are not dead when we are alive. We are not alive when we are dead. We live in a natural universe. The supernatural does not exist apart from man's imagination and his fondness for myth. Carl Sagan left us with these words, "Extraordinary claims require extraordinary evidence." Science is the candle, not religion, not mythology, not astrology. The Carl Sagan Center for the Study of Life in the Cosmos is being built in Washington, D.C. Southern Constellations We never see the constellations of the southern hemisphere from our latitudes because the tilt of the earth in its orbit is not great enough. To see the southern stars, we must journey to the equator. There are 88 constellations. 32 can only be seen from the southern hemisphere. Many of the southern constellations were named by the Frenchman, Nicolas Lacaille. Animals dominate. There are 2 mammals, 6 birds, 2 reptiles, 1 fish and 2 insects. ..1 Centaurus - centaur ..2 Lupus - wolf ..3 Pavo - peacock ..4 Tucana - toucan ..5 Grus - crane ..6 Apus - bird of paradise ..7 Phoenix - phoenix ..8 Columbia - dove ..9 Hydrus - water serpant 10 Chamaeleon - chamaeleon 11 Dorado - swordfish 12 Volans - flying fish 13 Music - fly The scientific tools belong to Lacaille. He was the last man to create constellations. 14 Horologium - pendulum clock 15 Pictor - painter's easel 16 Octans - octant 17 Circinus - compass 18 Antlia - air pump 19 Telescopium - telescope 20 Norma - carpenter's level 21 Ara - Altar 22 Reticulum - the net (in an eyepiece) 23 Fornax - furnace 24 Sculptor - sculptor 25 Caelum - chisel of the sculptor 4 groupings are part of the old constellation, Argo Navis, the ship on which Jason and The Argonauts sailed after The Golden Fleece. 26 Carina - keel of Argo 27 Vela - sail of Argo 28 Puppis - stern of Argo 29 Pyxis - ship's compass This leaves (30) Indus, the Indian, (31) Triangulum Australe, the southern triangle and the very symbol of the Southern Hemisphere, (32) Crux, The Southern Cross. The Cross points to the south celestial pole. Its 3 bright stars are called the 3 Marys. According to The Gospel of John, the 3 Marys at the cross when Jesus was crucified were his mother, the Virgin Mary, his mother's sister and Mary Magdalene. I understand Mary Magdalene being there. People have questioned whether she was Jesus' lover. What I do not get is why parents would give their daughters the same name. The 3 bright stars of the south are: 1 Canopus - Carina 2 Alpha Centauri - Centaurus 3 Achernar - Eridanus The missing piece of The Milky Way circle can be seen in the south. The Magellanic Clouds look like pieces of The Milky Way. On Michael's 18th birthday, March 11, 2002, I took American Airlines to L.A. and flew Qantas down to Sydney, Australia. We crossed the equator and international dateline at about the same place. I got a motel and took a train to Sydney Harbor. I saw the Opera House, the Harbor Bridge and the Rocks (Old Town). My purpose in going to Australia was to see the southern stars and constellations. Monte Wilson of the Astronomical Society of New South Wales (ASNSW) picked me up at the motel. We drove through the Blue Mountains to Wiruna, their Dark Sky Site, about 3 hours northwest of Sydney, for the South Pacific Star Party (SPSP) I was lucky. The weather was great all 3 nights. I got to stay in the house, referred to as the "White House" because they let Americans stay there. There was a couple named Tom and Lucy from Texas who proved invaluable. Lucy actually grown up in Louisville around the Bardstown Road area. "I saw The Southern Stars burning in their glory!" I saw The Southern Cross and The Coalsack next to it. I saw The Magellanic Clouds. They were fainter than I thought. I saw the bright stars, Canopus, Alpha Centauri and Achernar. Tom kept finding galaxies and nebulae in Tony Buckley's 20 inch. We looked at Jupiter and Saturn. Orion was upside down. Scorpius got straight up in the sky. The hub of The Milky Way in Sagittarius was high and prominent. I looked into our galaxy's thickest part, something I only saw along the horizon in the 1960s. The southern constellations are abstract. To trace out even Argo and Centaurus takes more time. Seeing Scorpius overhead is what stayed with me, that and seeing Scorpius and Orion in the sky at the same time. The southern sky is more glorious than the northern because we also get the bright winter stars we see here. I was impressed at how close Canopus is to Sirius and how the Southern Cross is not all that far below Scorpius. I will never forget when I walked out of the house that first night and looked up at the southern sky for the first time. It was a revelation! The whole sky was ablaze with stars! Treasurer Max Gardner drove me back to Sydney. He took me to his home and showed me some of the city. We crossed the Harbor bridge. We drove on the left side. Sydney is beautiful. Max explained how Australia is part of the British Commonwealth, that the Queen is head of state. Australia is a constitutional monarchy. I saw a book about Alaska in Max's bookcase. Crossing the Pacific again, I noticed how close we came to Hawaii. I wondered how long it would be before I saw Hawaii. I arrived back in Nashville, March 18, 2002. One week. Sydney is halfway between the equator and the south pole. I am thinking about Alaska. I will contact astronomy people in Anchorage and Fairbanks. The northern lights can be seen 240 nights a year in Fairbanks. I will fly to Anchorage, journey by train to Danali National Park to see Mount McKinley and then on to Fairbanks at the Arctic Circle. The northern lights, or Aurora Borealis, is caused when the solar wind hits gases in our upper atmosphere. The curtains, ribbons and waves of red, blue and green light can be spectacular. These lights occur at the poles because the earth acts as a magnet, pulling the particles of the solar wind north and south. A similar phenomenon occurs toward the south pole. We do not hear as much about it because the big population centers are in the north. Other planets have their northern and southern lights. A second astronomy trip can be to a Star Party at the Grand Canyon. The Tucson Astronomical Society meets at the Grand Canyon each June for a Star Party. This will be an ideal experience. I want Michael to see the Grand Canyon. There is a Las Vegas Astronomical Society. It would be nice to see the Perseids with them from the Valley of Fire. Cousin Larry is interested. Bibliography ..1 Apfel, Necia. Voyager To The Planets. New York, Clarion Books, 1991 ..2 Baker, Robert H. Introducing The Constellations. New York, Viking Press, 1957, ..3 ________. When The Stars Come Out. ..4 Bernhardt, Bennet & Rice. Handbook Of The Heavens ..5 Branley, Franklin M. The Milky Way: Galaxy Number One. ..6 Couper, Heather and Nigel Henbest. Space Scientist Series. New York, Franklin Watts, 1980s ..7 Fanning, A. E. Stars, Planets And Galaxies. ..8 Ferris, Timothy. Coming Of Age In The Milky Way. New York, William Morrow, 1988 ..9 ________. The Red Limit: The Search For The Edge Of The Universe. New York, William Morrow, 1977 10 Hathaway, Nancy. The Friendly Guide To The Universe. New York, Viking, 1994 11 Knight, David C. Galaxies: Islands In Space. New York, William Morrow, 1979 12 Moore, Partick. The Moon. 13 Muirden, James. The Amateur Astronomer's Handbook. Third Edition. New York, Harper & Row, 1983 14 Norton, O. Richard. Rocks From Space: Meteorites And Meteorite Hunters. Missoula, Montana, Mountain Press, 1994 15 Ride, Sally and Tam O'Shaughnessy. Exploring Our Solar System. New York, Crown, 2003 16 ________. The Mystery Of Mars. New York, Crown, 1999 17 ________. The Third Planet: Exploring The Earth From Space. New York, Crown, 1994 18 Sagan, Carl. Billions & Billions: Thoughts On Life And Death At The Brink Of The Millenium. New York, Random House, 1997 19 ________. Cosmos. New York, Random House, 1980 20 ________. Pale Blue Dot: A Vision Of The Human Future In Space. New York, Random House, 1994 21 ________. The Demon-Haunted World. New York, Random House, 1995 22 ________. Spangenburg, Ray and Kit Moser. A Look At Saturn. New York, Franklin Watts, 2001 23 Steel, Duncan. Target Earth: The Search For Rogue Asteroids And Doomsday Comets. Pleasantville, Reader's Digest, 2000 24 Wilford, John Noble. Mars Beckons: The Mysteries, The Challenges, The Expectations Of Our Next Great Adventure In Space. New York, Alfred A. Knopf, 1990 25 Zim, Herbert S and Robert H. Baker. Stars: A Guide To The Constellations, Sun, Moon, Planets And Other Features Of The Heavens. New York, Golden Press, 1975 Jim Colyer Originally written 1995-1996 Revised 2002-2006
Contact: jim@jimcolyer.com