Ancient people were fascinated by the sky and the patterns of the stars.
Little Notes
By Gregory Bodenhamer Ph.D.
Powerful Humanistic Development PeopleNology
GregoryBodenhamer@Live.com Nollijy Univerisity Research Institute Arts Science Technology Evolution
They noticed that the Moon changed its shape from night to night and changed its position against the stars.
They traced out constellations that looked like people and animals and made up stories about them.
The first astronomical observations were painted on the walls of caves 30,000 years ago. Ancient priests were among the first astronomers.
They studied the sky to make sure that their calendars, based on the changes of the Moon, were accurate.
At least 5,000 years ago, ancient astronomers began using large stones to chart the movement of the Sun and the stars.
The most famous ancient observatory of this kind is called Stonehenge, in England.
American Indians also built circles of stones lined up with the Sun and stars to figure out sunrise and the start of summer.
Some stars and constellations, like the Big Dipper, always stay in the northern part of the sky. Ancient sailors used these stars to guide them.
The Polynesians found their way to distant islands over the vast Pacific Ocean by watching the stars.
The Mayans, who lived in southern Mexico, watched the movements of the Moon and the planet Venus carefully
By about the year A.D. 800, they had worked out a calendar that was more accurate than the one being used in Europe at the time.
They may have built special buildings like this one to study the sky.
The lives of the ancient Egyptians depended on the Nile River. When the river flooded their fields, it made it possible for them to grow their crops.
Their priests carefully recorded when the floods came and found that they came about every 365 days.
So the Egyptians were the first to use a calendar with a 365-day year.
The ancient Babylonians viewed the universe as a disk of land with water surrounding everything.
They were the first people to study the movements of the planets and kept detailed records of their paths.
Like most ancient peoples, the Babylonians believed that studying planetary movements could help them predict the future.
One biblical story tells how the people of a Babylonian city tried to build a stairway to the stars--the Tower of Babel.
Early Greek astronomers probably picked up most of their knowledge from the ancient Babylonians.
Around 550 B.C., the Greek philosopher Pythagoras pointed out that the Evening Star and the Morning Star were really the same body.
Today, we know that this body is the planet Venus.
At that time most people thought that the Earth was flat. One early Greek view described the world as a floating disk inside a great hollow ball.
But later some Greek astronomers thought that the Earth itself might have the shape of a ball. Others even thought that the light of the Moon was really reflected sunlight.
Ptolemy described the Earth as a huge ball at the center of the
universe with the objects in the sky moving around it in great circles.
Each planet moved in a separate circle. The Moon was lowest. Then came Mercury, Venus, the Sun, Mars, Jupiter, and Saturn. The stars were farthest out.
To explain why the planets changed direction, Ptolemy, using the older calculations of Hipparchus, worked out a detailed scheme of the planetary motions.
Ptolemy did his work in about A.D. 150; Hipparchus, about 130 B.C. So it took about 280 years to come up with the scheme.
It was very complicated, but it could be used to work out future positions of the planets. © 1996, 1995 Zane Publishing, Inc., GARETH STEVENS, Inc., and CLEARVUE
In about 240 B.C., a Greek astronomer in Egypt, Eratosthenes, found that when the Sun was directly overhead in one city,
it cast a shadow in another city 500 miles (800 kilometers) to the north. Eratosthenes figured out this meant Earth's surface curved.
He also figured out that Earth was a ball about 25,000 miles (40,000 kilometers) around. Today, we know he was right.
After Ptolemy, Greek science faded, but the Arabs, beginning in A.D. 632, set up a large empire, discovered Greek books on science and mathematics,
translated them into Arabic, and studied them. In some cases, they improved on the Greeks.
In about 900, an Arab named al-Battani worked out new ways of figuring out planetary positions.
"Star-finders," or astrolabes, like this one, were created by Arab astronomers to solve complicated problems in astronomy.
One side often contained a detailed star map. If it hadn't been for the Arabs, Greek science might have been totally lost.
In July 1054, a star blazed out in the heavens. For three weeks it was so bright it could be seen in daylight. Europeans at the time took no interest,
and the only reason we know that the star appeared was because Arab, American Indian, Japanese, and Chinese astronomers carefully noted it.
Eventually, Europeans began to translate Arabic versions of Greek books into Latin. To many European astronomers, the Greek scheme of the universe seemed too complicated.
During the sixteenth century, the Polish astronomer Copernicus decided that a simpler scheme would be to place the Sun at the center of the universe
and have all the planets circle it.
Earth would have to circle the Sun, too. This seemed against common sense, but Copernicus wrote that his idea would make it much easier to figure out planetary positions.
For more than fifty years, astronomers argued whether Copernicus was right or not.
European astronomers were beginning to find out that the Greeks were indeed wrong now and then.
In 1572, a Danish astronomer, Tycho Brahe, spotted and studied a bright new star, or supernova, in the sky.
Eventually, the new star faded away. But the Greeks had thought that the sky never changed.
Tycho Brahe recorded the position of the supernova so precisely that modern astronomers have photographed its remains.
From his observatory in Denmark, Tycho Brahe also discovered that comets were farther from the Earth than the Moon.
But the Greeks had thought comets were inside our atmosphere.
All this made Europeans more ready to accept new ideas--like Copernicus's idea that the Earth circled the Sun.
The turning point came when a telescope was invented in Holland. An Italian astronomer, Galileo, heard of this, built his own, and in 1609 pointed it at the heavens.
He found that the Moon was a world with craters, mountains, and
what looked like seas.
He found that the planet Jupiter had four moons that moved about it, and that Venus changed shape, just as the Moon did.
At once he discovered many stars too dim to be seen without his telescope. All of this didn't fit with the Greek view of the Earth-centered universe.
But it did fit the views of Copernicus, and at that moment, modern astronomy had begun. Little Notes By Gregory Bodenhamer Ph.D. Powerful Humanistic Development PeopleNology GregoryBodenhamer@Live.com Nollijy Univerisity Research Institute Arts Science Technology Evolution
Today, in addition to optical telescopes, astronomers have instruments to pick up radio waves from objects too far away to see. They have even sent instruments into space.
We use these instruments to learn things that ancient astronomers never dreamed of.
But in many ways, we want to learn about the universe for many of the same reasons the first astronomers did long ago.
The Sun gives us light and warmth. North and south of the equator, when the Sun is low in the sky, the days become shorter and cooler, and winter comes.
Winter is a reminder that, without the Sun, there would be only darkness and freezing cold. So to the ancients, the Sun was a glorious and good god.
Different peoples had different images of the Sun god. The great eye of Ra represented the Sun god of the ancient Egyptians. Ra was considered the nation's protector.
This warm and tranquil "Sun-being" was drawn in Europe during the Middle Ages.
This fierce dragon gliding beneath the fiery Sun is from eighteenthcentury China.
The Moon is much dimmer than the Sun, but its light at night is cool and helpful. In myths, the Moon is usually pictured as a gentle female.
To the ancient Greeks, she was a beautiful maiden called Selene or Artemis. To the Egyptians, she was Isis.
As it circles Earth, the Moon changes its appearance, going from thin crescent to full and back to crescent each month.
Ancient calendars were based on this monthly cycle, and twelve of these monthly cycles made up the cycle of the seasons.
It therefore became very important to watch each month for the first sign of the new moon. In fact, both month and Monday come from the word moon.
From day to day and from night to night, the Sun and Moon change their positions against the stars in the sky.
So do five bright, starlike objects that we call planets, from the Greek word for "wanderers."
This is a view of brilliant Venus and dim Mercury as they line up at sunset with a crescent moon. Venus is the brightest planet in the sky and is named for the goddess of beauty.
Mercury is the fastest-moving planet and is named after the quickfooted messenger of the gods.
The ancient Babylonians watched the planets move across the sky and gave them the names of gods. The Greeks and Romans copied the Babylonians in this,
and we use the Roman names to this day. Mars is named after the god of war; and Saturn, after the god of agriculture.
The second brightest planet in the sky, Jupiter, was named for the chief god.
Jupiter is not as bright as Venus, but it shines all night, while Venus appears only in the evening or at dawn.
In modern times, people have found new planets that are too far away for the ancients to have seen. These planets have been given names from mythology, too.
Beyond ringed Saturn is Uranus, named for the god of the sky, who was Saturn's father. Farther still is Neptune, a sea-green planet named for the god of the sea.
Beyond Neptune is Pluto, named for the god of the underworld because it is so far from the light of the Sun.
Little Notes By Gregory Bodenhamer Ph.D. Powerful Humanistic Development PeopleNology GregoryBodenhamer@Live.com Nollijy Univerisity Research Institute Arts Science Technology Evolution
Every so often, something unusual happens in the sky: the Sun or Moon is eclipsed and hidden from our view.
The Sun is eclipsed because the Moon moves in front of it and hides its light.
During a lunar eclipse, the Moon's bright face is turned a dusky red as it slips into Earth's shadow.
Ancient people didn't know these causes, so they invented causes of their own. Some thought the Sun and Moon were chased by wolves, dragons,
or other monsters that caught up with them now and then. Here the Hindu dragon Rahu causes a solar eclipse as he tries to swallow the Sun.
Of course, the Sun and Moon have always come back from their eclipses.
And they will continue to do so for billions of years, even though according to Norse myths, at world's end a giant wolf will finally swallow the Sun.
Comets appear in the sky now and then. They are hazy objects with long tails.
With a little imagination, they might look like the heads of mourning women with long, streaming hair--and in fact, the word comet comes from the Greek word for "hair."
Sometimes comets look like swords, so people had several reasons to think of them as unpleasant omens. It's no wonder, then,
that most people thought comets were messages sent by the gods, warning of war, plague, and destruction.
People would pray or ring church bells in order to try to ward off the evil. But evil always came when there were comets in the sky.
Of course, evil always came when comets were not in the sky, too-but people somehow didn't notice that.
When you look at the stars, you may imagine that they form patterns. Some of these patterns are triangles, crosses, or squares. Some are shaped like a W.
Some form wiggly lines. Two bright stars might be close together and appear to be related when viewed from Earth.
Ancient people imagined many shapes in the sky, including even people and animals. These shapes made it easier to locate the stars.
A star might be in the "tail of the scorpion" or in the "head of the hunter." These patterns are called constellations,
a word that comes from two Latin words which basically mean "stars together." The constellations were given names, many of them in Latin.
The ancients also created stories about these imaginary figures in the sky.
The Sun, Moon, and planets each pass through the same constellations as they make a large circle in the sky. This circle was divided into twelve constellations,
so that the Sun took one month to go through each. Most of the constellations were pictured as animals,
so the band in which the planets move is known as the zodiac, which means "circle of animals."
In this thirteenth-century painting, celebrating the month of May, the Sun moves from the constellation Taurus (the Bull) into Gemini (the Twins),
while Venus, the love goddess, watches over the people on Earth from her blue chariot.
Some constellations in the Northern Hemisphere never set. One of these, Ursa Major (the Great Bear), contains the Big Dipper.
Sailors in old times noticed that Ursa Major was always in the northern sky.
This meant that they could look for it and always tell which direction was north. Thanks to the Dipper, sailors could voyage out of sight of land and find their way home.
We know that both ancient and modern cultures have seen figures in the constellations. Sometimes these figures are similar.
Babylonians as well as ancient Mongols saw the Milky Way as a seam sewn in the two halves of heaven. And several cultures from different times and places-the Sumerians,
Vikings, and some American Indians--believed the Milky Way was a bridge between Earth and the sky for the dead.
But most cultures differ in their reading of the stars. Indians, for instance, interpreted the dark clouds of the Milky Way,
The Inca
rather than the stars, and saw in them animals such as a bird, fox, llama, toad, and serpent.
To the Norsemen, it was a huge spike driven through the universe around which the heavens revolved. To the Mongols, it was the Golden Peg,
a stake that kept the heavens from whirling apart. likened it to an emperor, the chief star that ruled the others.
The Chinese
In India, it was the place where a holy young prince faithfully meditated. "It" is the Pole Star, that stable star in the north around which all others seem to revolve.
As shown here, the two stars at the end of the Big Dipper's bowl point toward the Pole Star. But, in reality, there has not been just one Pole Star.
Because Earth's axis wobbles a bit, various stars have been the Pole Star: Alderamin, Deneb, Vega, Thuban, and our current Pole Star, Polaris.
And, of course, during those years, there have been periods when there was no star exactly to the north.
People talk about objects in the sky in different ways. Astronomers talk about the skies in familiar ways.
But astrologers talk about the skies in ways that are less familiar. The practice of astrology, dating from ancient times,
is to work out methods for predicting the future by using the position of the planets in the zodiac.
Even today, many newspapers carry a horoscope for those who seek advice from the stars.
Astronomers, who use the methods and tools of modern science, are skeptical about astrology. Yet many people believe it to be true,
just as ancient peoples found their stories of the skies to be true. So history shows us that while we are still uncovering secrets about the universe,
one thing remains certain: our endless desire to make sense out of the objects above and around us.
In ancient times, astronomers learned a great deal about how the Sun, Moon, and planets moved across the sky by simply gazing skyward.
They figured out the length of the year and worked out calendars.
Nowadays, astronomers still look at the sky. But today they have new ways of collecting information from the sky, and they have new ideas about how the universe works.
What's more, astronomers are always developing even newer and better instruments.
The best-known instruments of astronomers today are the large telescopes. In 1948, on Mount Palomar in California, this telescope with a mirror 200 inches (about 5 meters
across was installed. It collects 360,000 times as much light as the human eye does.
In 1974, the Soviet Union built a telescope in the Caucasus Mountains with a mirror 236 inches (about 6 meters) across.
Now, even bigger and more effective telescopes are in the works.
This is a model of the Keck Telescope in Hawaii, which will use thirtysix small mirrors, all coordinated by computer, to create a mirror twice as wide as Palomar's.
And scientists are developing newer types of glass to make telescopes both stronger and lighter.
But it doesn't matter whether the telescope is in an observatory or in your bedroom window: all telescopes on Earth have problems. Clouds and fog hide the sky.
The atmosphere absorbs some kinds of light. It scatters light by day so you can't see the stars. Even on clear nights, the air can be unsteady, causing the stars to quiver.
The United States put a large telescope--the Hubble Space Telescope--into orbit beyond Earth's atmosphere.
From there, it will help us see farther and more clearly into the cosmos. It will show us distant galaxies, and it will be our "eyes," peering deep into star clusters.
Little Notes By Gregory Bodenhamer Ph.D. Powerful Humanistic Development PeopleNology GregoryBodenhamer@Live.com Nollijy Univerisity Research Institute Arts Science Technology Evolution
Here are two simulated views of a distant star cluster as seen from Earth (on the left) and through the Hubble Space Telescope (on the right).
The clarity with which the space telescope will gather light from near and deep space will help us figure out how large and how old the universe is.
It will help us know more about the very farthest edges of the universe.
Stars give off radio waves as well as light, so we have built special radio telescopes that concentrate and receive radio waves.
Radio waves can give us information that light does not. This is M31, the closest spiral galaxy to us, as seen by radio waves.
This is M31 as seen by visible light. something different about this spiral galaxy.
Each method shows us
Radio waves have helped us discover very distant objects. In 1967, a young British astronomer, Dr. Jocelyn Bell Burnell, detected strange,
steady radio signals from deep space. She had discovered pulsars-rapidly spinning neutron stars sending out radio signals with each turn.
Scientists can use computers to make a number of small telescopes work together exactly as if they were one large telescope.
Here, an array of small radio telescopes have been electronically combined to function as one "superscope."
These radio telescopes are part of the VLA--Very Large Array--in Socorro, New Mexico. Each arm of the VLA is 13 miles (21 kilometers) long.
Thanks to computers, radio telescopes that are thousands of miles apart can detect radio waves more sharply than ordinary telescopes see light.
Computers also help analyze the data that telescopes receive and study it with great precision. Thanks to computers, astronomers can now see dim stars,
remote galaxies, and other distant objects in the sky more sharply than ever before. Here, an astronomer studies an image produced by radio telescopes.
As we see objects that are farther and farther off in space, we also see them as they existed longer and longer ago. Traveling at about 186,000 miles (300,000 kilometers) per second, light from the nearest star other than our Sun takes over four years to reach us.
Light from the Andromeda Galaxy, a relatively close galactic neighbor, takes over 2 million years to get here.
Quasars are distant objects with very bright centers. We see them by light that left them from 1 to 10 billion years ago.
Radio telescopes created this image of a huge gas jet erupting from quasar 3C -273.
Right now, our best instruments can detect distant galaxies by light that left them 17 billion years ago.
All of this suggests something about how old the universe might be and the way in which it might have developed after it came into being.
Every once in a while, a star explodes and briefly shines with the light of a billion ordinary stars.
The latest known supernova appeared in February 1987 in the Large Magellanic Cloud, a galaxy only about 160,000 light-years from us.
The bright spot (on the left) is Supernova 1987A. When a supernova explodes, most of its matter is scattered through space.
Minutes before astronomers detected the explosion of Supernova 1987A, a smattering of small particles called neutrinos, given off by the dying star,
passed through neutrino detectors like this one on Earth. Here, a diver is working inside the water-filled particle detector.
Over 2,000 light sensors watch for the telltale flashes that occur when neutrinos are captured.
This is a computer image showing which sensors have detected the flash from a passing neutrino.
Being an astronomer is fun, but it can be hard work. It may mean staying up all night to observe the skies and spending countless hours examining data for days, weeks,
and even months on end. If this sounds unpleasant, keep in mind that the excitement of making a new, important discovery makes all the hard work worthwhile.
There is no shortage of objects to observe in the sky, and many of those who look for these objects are amateurs. These people are not professionals,
but they are fascinated by the sky. They keep looking at the sky night after night, recording their findings, taking photographs, and drawing sketch
Amateur astronomers are often the ones who discover new comets, observe meteors, and keep track of stars that change in brightness
Sometimes they even spot a nova, a star that suddenly increases very much in brightness. This photo of a total solar eclipse was taken by an amateur astronomer.
Sometimes amateur astronomers make interesting observations with little more than a pair of high-quality binoculars.
Others buy or construct small telescopes. This amateur telescope features a drive mechanism and a computer readout.
Sometimes it's hard to tell the difference between an amateur astronomer and a professional astronomer. One amateur, Asaph Hall, was a carpenter,
but he loved astronomy. He got a job at the Harvard Observatory as an assistant and eventually discovered the satellites of Mars
Clyde Tombaugh was too poor to go to college, but he got a job as an assistant at Lowell Observatory and eventually discovered the planet Pluto.
Astronomy takes equipment, patience, and luck. But it also takes a lot of thinking about science and mathematics. Albert Einstein was not an astronomer,
but he figured out an explanation of how gravity and other forces in the universe might work. This explanation, called the general theory of relativity,
has helped astronomers decide what to look for in the cosmos.
In 1936, Albert Einstein said that light from a distant star would curve around another star on its way toward Earth. We would thus see the distant star not as a point of light,
but as a ring of light. This ring is called a gravitational lens, or Einstein ring. In 1988, half a century after Einstein's explanation,
astronomers observed this light from one galaxy bending--forming an Einstein ring--
as it passed by another galaxy. So far, everything astronomers have found has backed up Einstein's theories.
Despite all the history and all the work with all the instruments, astronomers don't have all the answers. They don't know just how old the universe is,
or exactly how it came into existence, or just how it may have developed from a tiny object into the huge, galaxy-filled universe that now exists.
Most modern astronomers agree that the universe is expanding, but
they don't know if it will expand forever or start contracting again someday.
There may be parts of the universe we can't detect, but we don't know what these missing parts may be composed of.
Will we ever have all the answers? Probably not. For many people, not having all the answers seems itself to be a big problem.
But then, problems make life more interesting, and they certainly make astronomy more exciting.
The sky changes as we watch. Through the night, we see stars rise and set, turning in large circles about a spot in the sky near the North Star, Polaris.
That's because Earth is turning on its axis. Polaris is called the North Star because it is almost directly above Earth's North Pole.
As a result, it doesn't move, but always stays in the north.
As you might guess, the brightest object in the night sky is the Moon. The Moon shines by reflected light from the Sun.
When the Moon and Sun are on opposite sides of the Earth, we see the Moon's lighted side as a "full moon," shining all night.
When the Moon and Sun are on the same side of the Earth, we face the Moon's unlighted side. Perhaps we see just a bit of the lighted side as a crescent just after sunset.
From night to night, the crescent gets thicker until there is a full moon, and then thinner and thinner until there is a "new moon."
The Moon goes around the Earth in a little less than a month. In that time, we see all its shapes, or phases, in order.
A group of stars in the sky that seems to trace out a pattern or figure is called a constellation.
Many of the constellations we see in the Northern Hemisphere are named after the gods and heroes of ancient Greek mythology
or after objects that were used in ancient times. The pattern of these stars reminded the ancient Greeks of Sagittarius (the Archer).
From the Northern Hemisphere, we can see certain constellations that always appear to circle Polaris.
Here, two of these constellations have been connected by imaginary lines. On the left is the constellation called the Big Dipper.
The two stars at the bowl end of the dipper are called the "pointers." An imaginary arrow through them "points" at Polaris.
On the other side of Polaris are five stars in a W shape. constellation is Cassiopeia (the Queen).
This
There are also some stars that circle a point above the South Pole, opposite Polaris. A constellation called the Southern Cross, composed of four bright stars,
points to the place the southern stars circle about. Northern Hemisphere, we can never see this part of the sky.
But in the
If you looked in the northern sky at the same time each night, you'd see that, from night to night, the patterns in the sky shift.
A pattern of stars at midnight on one night won't return exactly until a whole year has passed. So the patterns change with the seasons.
That's because Earth revolves around the Sun. In summer, the Big Dipper and Cassiopeia would be positioned something like this.
In the autumn, they would have moved to be positioned like this.
Little Notes By Gregory Bodenhamer Ph.D. Powerful Humanistic Development PeopleNology GregoryBodenhamer@Live.com Nollijy Univerisity Research Institute Arts Science Technology Evolution
In winter, they would look like this;...
...and in spring, like this.
Not until the next summer at the same time--after a whole year has passed--will they appear in the same location in the sky.
In the next pictures, you should imagine that you are looking up at the night sky facing toward the south. As you face south,
imagine that the top of the picture is folded toward you and passes over your head. The bottom of the picture would then be south, and the top would be north.
As you face south in the spring and look way up over your head, the Big Dipper will stretch across the sky above you.
If you follow the curve of the handle of the Big Dipper back toward the southern part of the sky, you will come upon the kite-shaped constellation Bootes (the Herdsman).
Arcturus, one of the brightest stars in the spring sky, is part of Bootes. If you continue to follow the imaginary curve south,
you will come to the constellation Virgo (the Maiden) and its bright star, Spica.
To the west of Virgo (right as you face south) is the constellation Leo (the Lion) with its bright star, Regulus.
One of the easiest constellations to spot in the summer sky is Sagittarius (the Archer). Its outline looks something like a teapot in the southern sky.
The Milky Way, a band of foggy light that encircles the sky, passes through Sagittarius. To the west, right of Sagittarius, is a curve of stars.
This constellation is Scorpius (the Scorpion) with its bright red giant star, Antares. Over your head as you face south is Lyra (the Lyre) with its bright star, Vega.
To the east of Lyra, shaped like a great cross, is Cygnus (the Swan). Halfway between Cygnus and Sagittarius is the bright star Altair, in Aquila (the Eagle).
The three stars Vega, Deneb, and Altair form a star pattern we call the summer triangle.
The constellation Pegasus (the Flying Horse) is high up in the autumn sky, nearly overhead as you face south. Its four bright stars form the Square of Pegasus.
Attached above and to the left of the Square of Pegasus is Andromeda (the Chained Maiden).
Andromeda is exciting because within it, you can just barely spot a small, foggy patch of light.
If we looked at this patch through a telescope, it would turn out to be a huge collection of stars called the Andromeda Galaxy.
To the southeast of Pegasus (lower left as you face south) is Cetus (the Whale) which has a rather dim star that is variable. A variable star grows brighter, then dimmer.
When astronomers first saw this star, this changing brightness seemed so unusual that they named the star Mira, which means "wonderful."
In the cold winter sky, you can see Orion (the Hunter). This beautiful constellation can help you find other star groups in the winter sky.
On Orion's northeastern edge (the upper left, as you face south) is the huge red giant star called Betelgeuse. Orion's southwestern edge (lower right) is marked by Rigel,
a star about 55,000 times brighter than our Sun. Between these two bright stars is a row of three stars--Orion's belt.
Below the belt is another row of stars--Orion's sword. The middle "star" of the sword is actually the Orion Nebula.
Through a telescope, the Orion Nebula is seen as a giant gas cloud in which stars are born.
Orion's belt points down and to the left (southeast) at the bright star Sirius, in Canis Major (the Great Dog). Sirius is the brightest star visible from Earth--not counting the Sun,
of course. The belt also points up and to the right (northwest) toward Aldebaran, the brightest star in Taurus (the Bull).
Taurus is one of the twelve constellations of the zodiac.
The zodiac constellations, represented here on a plate, form a band across the sky that includes the paths of the Sun, the Moon, Mercury, Venus, Mars, Jupiter, and Saturn.
The Moon moves through the constellations of the zodiac in a little less than a month. The Sun moves along the same path,
but moves much more slowly, staying in each constellation for one month and making its complete circuit in a year.
Because Venus and Mercury are closer to the Sun than we are, we always see them near the Sun. When the Sun sets,
Venus is sometimes in the western sky as the brilliant Evening Star, setting a couple of hours later. Mercury is even closer to the Sun, but it is dimmer,
so it is harder to observe. This is a view of brilliant Venus and dim Mercury as they line up at sunset with a crescent moon.
Mars, Jupiter, and Saturn can all shine in the midnight sky, but through a telescope you can see Jupiter as a small globe and Saturn with its bright ring.
There are still farther planets: Uranus, Neptune, and Pluto. You can see Uranus and Neptune easily with a small telescope, but you need a large one to see Pluto.
Telescopes come in two varieties: refracting and reflecting. Refractors, like this one, use lenses to concentrate the light,... Little Notes By Gregory Bodenhamer Ph.D. Powerful Humanistic Development PeopleNology GregoryBodenhamer@Live.com Nollijy Univerisity Research Institute Arts Science Technology Evolution
...a large mirror bounces and focuses light onto a smaller mirror, which bounces it into the eyepiece.
With telescopes, we can see far-off celestial objects. Through large telescopes,
astronomers have taken photographs like this one of the spiral Whirlpool Galaxy --M51, which looks like a fuzzy pinwheel--...
...or of the Helix Nebula, a faint shell of gas blown off an aging star.
But even a small telescope can give you an idea of the vastness of the universe and the wonder of the stars.